Argh! SES Light Will NOT Go Out! *solved- Bosch sensor fail!

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Argh! SES Light Will NOT Go Out! *solved- Bosch sensor fail!

Post by belstsrv »

Hi everyone. First time poster.

I have a 2004 S10, totally stock. A couple of months ago the SES light came on. I am fairly mechanically inclined, but this is my first time trying to troubleshoot anything like this. I'll try to run down the history as best as I can...it has been a LOOOONG 2 months trying to get to the bottom of this...

First time reading the codes it showed the MAF sensor code (can't recall code) and P1055.

I had no idea what the MAF sensor code was. In the past SES light meant O2 sensor. I saw the O2 sensor code and moved along. I gave the code to the guy at a parts store who pointed me to the wrong O2 sensor. Replaced that sensor, light came back on. MAF sensor and O2 sensor. This time I looked up the code and realized I had replaced the wrong sensor. Got another O2 sensor and replaced it. Because my dad used to own a local NAPA store I can get parts at cost so I just replaced the second sensor although maybe I should have swapped them. At this time I also did not know there was a 3rd sensor either so I figured may as well replace both. Now I know there are 3 . Also pulled out the MAF sensor and cleaned it with rubbing alcohol and a Q-Tip. The MAF sensor was quite dirty.

Also took the truck and had a tune up done on it. Replaced plugs, wires, cap. rotor, fuel filter. Ran some injector cleaner through it as well.

So...drive it a little, light comes back on. Same P0155 code. Reset code. I go to my dads for the weekend to do some brake work on the truck and also flush the radiator. At that time, I replaced the Bank 2, Sensor 1 O2 sensor thinking maybe I got a bad one and that was causing the light to keep coming on.

On way home from dads (about 1 hr in to drive), light comes on. Stop on way home and read codes, now I am getting P1055 and also a coolant temp warning. I check on the coolant code and that points to bad thermostat. I check the running temp and sure enough, its low. Replace T-Stat (stock 195 degree). Reset codes.

Driving around, temp is good, light is off.

Cold start, light back on...P1055. I reset the light. I think I recall reading how the O2 sensor is somehow linked to the coolant temp for some of its tests so I am thinking that failure may have been logged before I replaced the T-Stat.

Cold start this morning, light back on. P0155 code again.

If there was a bridge on my way to work, I may have driven off it

I can't believe how much of a pain in the rear this has been...

Let me give some other info that may help.

Other than the trip to my dads which is about 1.5 hours (some highway, some rural), my daily commute is 3-4 miles to and from work or the gym or to kids activities.

Could the light be turning on due to lack of a real drive cycle being done? I just pulled the requirements for the GM drive cycle and I am 99% sure I am not hitting these requirements. Could the light be coming on because I am not making it through a cycle after I reset the light?

Or, is the light back on after a reset due to an actual problem?

Other than the O2 sensor, the other codes have never come back on after I performed some maintenance on those items (cleaned MAF, replaced T-Stat).

The truck is running well. Maybe slightly low/rough on idle at a stop, but I am not certain about that. No hesitation or performance issues at all in general.

Are there other things I can do to test this out?

With everything I have done, I feel like taking it to a shop will end up in a wild goose chase and cost me tons of cash. In fact, when I took it in once to have a diagnostic run, the guy said since I had replaced the O2 sensor and that was the code that they'd just reset it and I should drive it.

Looking for some advice...thanks everyone!
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Re: Argh! SES Light Will NOT Go Out! - Help :)

Post by roadrunner »

I know this will sound simplistic but have you checked your oxygen sensor fuse in the panel under the hood? If it is blown you may have/had shorted heater circuit wires to one or more of the O2 sensors.
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Re: Argh! SES Light Will NOT Go Out! - Help :)

Post by HenryJ »

The code you are dealing with is the bank 2 O2 sensor heater circuit. That is why it comes on during cold start.
The heated circuit in the oxygen sensor decreases time needed to enter closed loop. As the O2 heater reaches operating temperature, the oxygen sensor responds by switching according to oxygen content of the exhaust surrounding it. The ECM tracks how long it takes for the oxygen sensor to begin switching. It the ECM determines (based on coolant temp) that too much time elapsed before the oxygen sensor began operating properly, it will set P0155.

I too would look for shorted wiring , or bad connections.

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Re: Argh! SES Light Will NOT Go Out! - Help :)

Post by belstsrv »

Just got under the truck. I followed the wires from that sensor towards the motor as best as I could and did not see or feel any spots that might be bad.

I took my multimeter and did a continuity test between the wires of the plug and did not detect any shorts here either.

Are there certain voltages or something on the plug that I could test for?

I did check the oxygen fuse as well and it was Ok too. What are some other troubleshooting steps I can take for this?

Thanks for your help!
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Re: Argh! SES Light Will NOT Go Out! - Help :)

Post by HenryJ »

GM Data wrote:DTC P0135 or P0155
Circuit Description

The heated oxygen sensor (HO2S) is a sensor designed to create a voltage relative to the oxygen content in the engine exhaust stream. The control module supplies the HO2S with signal high and low circuits. Voltage and ground are supplied to the HO2S heater and is commanded ON or OFF by the control module. The oxygen content of the exhaust indicates when the engine is operating lean or rich. When the HO2S detects that the engine is operating rich, the signal voltage is high, and decreases the signal voltage as the engine runs leaner. This oscillation above and below the bias voltage, sometimes referred to as activity or switching, can be monitored with the HO2S signal voltage.

The HO2S contains a heater that is necessary in order to quickly warm the sensor to operating temperature. The heater also maintains the operating temperature during extended idle conditions. The HO2S needs to be at a high temperature in order to produce a voltage. When the HO2S reaches operating temperature, the control module monitors the HO2S bias, or reference, voltage. The control module the HO2S signal voltage for Closed Loop fuel control. During normal Closed Loop fuel control operation, the control module will add fuel, or enrich the mixture, when the HO2S detects a lean exhaust content. The control module will subtract fuel, or lean-out the mixture, when the HO2S detects a rich exhaust condition.

This diagnostic trouble code (DTC) determines if the HO2S heater circuit is functioning properly by monitoring the time required for the HO2S to reach the operating temperature. This DTC sets when the powertrain control module (PCM) fails to detect HO2S voltage transitions above and below the bias range within a specified amount of time.
Conditions for Running the DTC

* DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0200, P0300, P0440, P0442, P0446, P0452, P0453, or P1441 are not set.
* The HO2S voltage is between 425-475 mV at engine startup.
* The intake air temperature (IAT) and the engine coolant temperature (ECT) are less than 50°C (122°F), and are within 8°C (14.5°F) of each other at engine start-up.
* The ignition 1 signal is between 9-18 volts.
* Intrusive tests are not in progress.
* The scan tool output controls are not active.

Conditions for Setting the DTC

The HO2S voltage remains within 150 mV of the startup voltage for a predetermined amount of time, based on ECT and air flow.
Action Taken When the DTC Sets

* The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
* The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

* The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
* A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
* A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
* Clear the MIL and the DTC with a scan tool.

Diagnostic Aids

Important

Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing or replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM.

* Use the Freeze Frame/Failure Records in order to help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Freeze Frame/Failure Records can help to determine how many kilometers (miles) have occurred since the DTC set. The Fail Counter and the Pass Counter can also help determine how many ignition cycles the diagnostic reported a pass or a fail. In order to isolate when the DTC failed, operate the vehicle within the same Freeze Frame conditions such as RPM, load, vehicle speed, temperature, etc., that you observed. For an intermittent condition, refer to Intermittent Conditions . These conditions include:
o The RPM
o The vehicle load
o The vehicle speed
o The temperature
* The heater diagnostic will only run on a cold start and run once per ignition cycle.
* An oxygen supply inside the HO2S is necessary for proper operation. The HO2S wires provide the supply of oxygen. Inspect the HO2S wires and inspect the connections for breaks or for contamination. Refer to Heated Oxygen Sensor (HO2S) Wiring Repairs in Wiring Systems.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

2. After the HO2S heater is commanded ON, the HO2S heater heats up causing the HO2S signal voltage to either increase or decrease. This indicates that the HO2S heater is OK.
6. Both HO2S sensors must be disconnected to isolate a short to ground in the HO2S heater high control circuit.
10. Resistance within the specified range indicates the HO2S heater is OK.


1 Did you perform the Diagnostic System Check-Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2
Important

If DTC P0300 is set, diagnose that DTC first. Refer to DTC P0300 .

Important

Allow the engine to cool for one-half hour before proceeding with this diagnostic. This allows the HO2S signal voltage to return to bias voltage, approximately 447 mV.

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. Command the HO2S heater ON with a scan tool.
4. Immediately observe the affected HO2S voltage for 2 minutes.

Does the HO2S voltage go from bias voltage to more than or less than the specified range? 300-600 mV

Yes Go to Step 3

No Go to Step 4

3
1. Observe the Freeze Frame/Failure Records data for this DTC.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text, or as close to the Freeze Frame/Failure Records data that you observed.

Does the DTC fail this ignition?

--

Yes Go to Step 4

No Go to Intermittent Conditions

4
Are both DTC P0135 and P0155 set?

--

Yes Go to Step 6


No Go to Step 5

5
1. Turn OFF the ignition.
2. Disconnect the affected HO2S connector.
3. Probe the HO2S heater high control circuit with a test lamp connected to a good ground.
4. Turn ON the ignition, with the engine OFF
5. Command the HO2S heater ON with a scan tool.

Does the test lamp illuminate?

--

Yes Go to Step 7

No Go to Step 8

6
1. Disconnect HO2S bank 1 sensor 1 connector.
2. Disconnect HO2S bank 2 sensor 1 connector.
3. Probe the HO2S bank 1 sensor 1 heater high control circuit with a test lamp connected to a good ground.
4. Turn ON the ignition, with the engine OFF.
5. Command the HO2S heater ON with a scan tool.

Does the test lamp illuminate?

--

Yes Go to Step 7


No Go to Step 8

7
1. Connect a test lamp between the affected HO2S heater high control circuit and the HO2S heater low reference circuit.
2. Command the HO2S heater ON with a scan tool.

Does the test lamp illuminate?

--

Yes Go to Step 9

No Go to Step 11

8
1. Disconnect the PCM connector containing the HO2S heater high control circuit. Refer to Powertrain Control Module (PCM) Replacement .
2. Test the HO2S heater high control circuit for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Yes Go to Step 16

No Go to Step 12

9
Important

Perform the following test on HO2S bank 1 sensor 1 and HO2S bank 2 sensor 1. A condition in either sensor will cause this DTC to set.

Test the HO2S heater high control circuit, sensor side, for a short to the HO2S body. Refer to Circuit Testing in Wiring Systems.

Did you find the condition?

--

Yes Go to Step 15

No Go to Step 10

10
Important

Perform the following test on HO2S bank 1 sensor 1 and HO2S bank 2 sensor 1. A condition in either sensor will cause this DTC to set.

Measure the resistance between the HO2S heater high control circuit, sensor side, and the HO2S heater low reference circuit, sensor side. Refer to Circuit Testing in Wiring Systems.

Does the resistance of either sensor measure above or below the specified range?
2-50 ohms

Yes Go to Step 15

No Go to Step 13

11
1. Disconnect the PCM connector containing the HO2S heater low reference circuit. Refer to Powertrain Control Module (PCM) Replacement .
2. Test the HO2S heater low reference circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Yes Go to Step 16

No Go to Step 12

12
Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Yes Go to Step 16

No Go to Step 14

13
Inspect for poor connections at the harness connector of the affected HO2S. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Yes Go to Step 16

No Go to Step 15

14
Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement .

Did you complete the replacement?

--

Yes Go to Step 16

--

15
Replace the affected HO2S. Refer to Heated Oxygen Sensor (HO2S) Replacement Bank 1 Sensor 1 or Heated Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 1 .

Did you complete the replacement?

--

Yes Go to Step 16

--

16
1. Use the scan tool in order to clear the DTCs.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC run and pass?

--

Yes Go to Step 17

No Go to Step 2

17
With a scan tool, observe the stored information, Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?

--

Yes Go to Diagnostic Trouble Code (DTC) List

No System OK

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Re: Argh! SES Light Will NOT Go Out! - Help :)

Post by killian96ss »

You replaced all 3 O2 sensors right? What brand of O2 sensors are you using? From my experience and what I've learned over the years from other GM vehicle owners is that most GM vehicles have problems running anything other than genuine AC Delco O2 sensors. The most common problems are reduced gas mileage, surging, rough idle, increased emissions, too rich, too lean, etc. I don't know for sure if this is your problem, but if nothing else works, get some real AC Delco O2 sensors. For now double check the wiring and plug connections on the bank 2 sensor. If everything still looks good try swapping the bank 1 sensor over to bank 2 and see if the bank 2 problem goes away. The bank 3 sensor is only used by the pcm to determine if the cat is working properly, while # 1 and #2 are used by the pcm to control the air/fuel ratio.

Steve
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Re: Argh! SES Light Will NOT Go Out! - Help :)

Post by HenryJ »

I have a set of use sensors in the classifieds if you need them to solve this problem. They were error free.

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Re: Argh! SES Light Will NOT Go Out! - Help :)

Post by killian96ss »

HenryJ wrote:I have a set of use sensors in the classifieds if you need them to solve this problem. They were error free.
If all else fails, this would be a good option, especially when you consider how expensive new GM sensors are. :thumb:

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Re: Argh! SES Light Will NOT Go Out! - Help :)

Post by belstsrv »

killian96ss wrote:You replaced all 3 O2 sensors right? What brand of O2 sensors are you using? From my experience and what I've learned over the years from other GM vehicle owners is that most GM vehicles have problems running anything other than genuine AC Delco O2 sensors. The most common problems are reduced gas mileage, surging, rough idle, increased emissions, too rich, too lean, etc. I don't know for sure if this is your problem, but if nothing else works, get some real AC Delco O2 sensors. For now double check the wiring and plug connections on the bank 2 sensor. If everything still looks good try swapping the bank 1 sensor over to bank 2 and see if the bank 2 problem goes away. The bank 3 sensor is only used by the pcm to determine if the cat is working properly, while # 1 and #2 are used by the pcm to control the air/fuel ratio.

Steve
Well, Friday the light was back on. Reading the codes indicated P0141, which was the only sensor that I had not replaced. So, I replaced that one as well.

The sensors I am using are Bosch from Napa. I drove the truck all weekend, including a 40-50 minute ride and then the same ride back home. Just as a test, I started it last night (truck was in the garage) and it was OK.

Started it this AM (in the garage again) and the freaking light was back on!!!

Drove straight to Advanced Auto to read the code, P0155 AGAIN!

I am really at my wits end here...BTW...truck is past due on inspection and I need to resolve this to get it inspected. This is like a bad movie...fix something...drive to get through a drive cycle for inspection...light comes on...repeat...arrrgh!
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Re: Argh! SES Light Will NOT Go Out! - Help :)

Post by killian96ss »

Well, this is probably not what you want to hear, but most of the problems I have experienced with aftermarket O2 sensors are made by Bosch. I have personally had a bad experience with this brand, as have a few friends of mine with GM vehicles. If Brule (henryj) will give you a good deal on his used 02's, I would try it out. I cannot guarantee that trying different O2's will solve your problem, but it seems like different O2's might help. Do you have access to a scan tool that displays O2 sensors reading in millivolts? My Actron scanner allows you to view O2 readings in real time which shows the actual air/fuel ratio and millivolt readings as the pcm tries to maintain the optimum air/fuel ratio. It is very helpful in troubleshooting problems like this! I am also curious if your fuel pressure is high enough or if you have an injector problem. Any problems in the fuel system will directly affect the O2 sensors and how well the pcm can compensate. For example if your fuel pressure is too low, the fuel injectors will not properly atomize the gas resulting in inconsistent delivery and probably a lean condition, or if you have leaking injectors you will have uneven distribution of gas and most likely a rich condition. Try checking the fuel pressure with the key on, engine off, and then check it again with the engine running. With the key on engine off, the pump should prime and then hold that pressure for several minutes before dropping off. If it drops right after priming, you have a leaking injector or a bad foot valve in the pump. Either one will cause problems. I dont have a manual in front of me right now, but I believe the fuel pressure should be at least 60 psi, but double chack that #. :wink:

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Re: Argh! SES Light Will NOT Go Out! - Help :)

Post by roadrunner »

I know it seems like a lot of messing around but HenryJ has given you the diagnostics as they are written in the manual. Mine says the same thing. I think you are in for a lot of tedious diagnosis and need to follow the steps in his post to solve/find your problem.
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Re: Argh! SES Light Will NOT Go Out! - Help :)

Post by ApproachMedium »

This is crazy. Bosch sensors dont play well? So let me guess, if I changed one of my two bank 1 sensors to a bosch, and the one bank 2 sensor, but not the one on my driver side... could that not throw codes for 02 sensors but give me other engine DTC troubles? I have a feeling I will be visiting the chevy dealer this weekend and buying a set of 3 new GM O2 sensors just to try and see...
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Re: Argh! SES Light Will NOT Go Out! - Help :)

Post by belstsrv »

Thanks for all the feedback so far. Light was off for the past 2 days and then came back on this morning as I started the truck. I have not read the code yet. Guessing it is P0155 again.

While is seems crazy that the part NAPA has will not do the job, I suppose anything is possible. I just can't describe how annoying this is/has been :)

In reading the troubleshooting info, I do not think I have all the tools required to follow that through. I do not think I have what I need to even test the fuel pressure.

Not sure what to do now.

Should I be looking to take this to a dealer?
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Re: Argh! SES Light Will NOT Go Out! - Help :)

Post by HenryJ »

Do you have a local repair shop that can help you out? Some auto part chain stores rent diagnostic tools. A fuel pressure gauge can be rented, or even purchased reasonably. Tools are not a bad investment. Sometimes cheap when compared to shop rates.

Have you swapped the sensor to the other bank? If you can prove it faulty, it should still be under warranty through the parts store from which you purchased it.

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Re: Argh! SES Light Will NOT Go Out! - Help :)

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HenryJ wrote:Do you have a local repair shop that can help you out? Some auto part chain stores rent diagnostic tools. A fuel pressure gauge can be rented, or even purchased reasonably. Tools are not a bad investment. Sometimes cheap when compared to shop rates.

Have you swapped the sensor to the other bank? If you can prove it faulty, it should still be under warranty through the parts store from which you purchased it.
Unfortunately I do not have a local shop that I've developed a relationship and some trust with. I could ask some friends for some recommendations though.

The Bank 2, Sensor 1 (P0155) sensor has been replaced twice now. I did the initial replacement and then returned that one for another one a couple weeks ago. I am thinking the odds are really stacked against 2 faulty ones in a row.

Have you ever had to run through those steps in the troubleshooting guide? Just wondering how difficult that would be to complete myself.

Thanks again.
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Re: Argh! SES Light Will NOT Go Out! - Help :)

Post by HenryJ »

Just swapping two of the same new sensor may not rule out a problem. New parts can be bad too. Swapping them side to side for a known good sensor rules out the sensor. If the problem does not change. Then you must proceed to a wiring or connector problem. If it moves , fault the sensor.
Make darn sure that one of the connector pins did not get bent during all this swapping.

I have used some of the steps in the flow chart. I can only remember once that it came to testing voltages before I found the problem.
A multimeter is not very expensive and you should have one. It is worth doing some testing if you are so inclined.

For mechanics, the dealer does not guarantee a good one. They are as much a roll of the dice as some other repair shops. That said , they do get more training sometimes and they do have the latest information available.
Asking around is the best idea. Ask at the local parts store. They know who buys the good parts and the "right" parts. They know who just throws parts at a problem and who takes the time to find the right fix first.

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Re: Argh! SES Light Will NOT Go Out! - Help :)

Post by belstsrv »

I do have a good digital multimeter, so that much is covered. What I am lacking is the scan tool to be able to trigger the O2 sensors on and such as the troubleshooting steps recommend.

Perhaps I can borrow / rent one from someplace though and try to work through some of the steps.
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Re: Argh! SES Light Will NOT Go Out! - Help :)

Post by HenryJ »

They will trigger on when you turn to the run position. They will not stay on like the scan tool can command, but you can still do the testing.
Swapping a known good sensor from the other "code free" bank and looking for a transfer first is a good idea.

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Re: Argh! SES Light Will NOT Go Out! - Help :)

Post by belstsrv »

Wanted to get back to everyone about the resolution of this issue. In the end, I did need to replace the thermostat because of that code. But the true root cause of the light not going out was the Bosch sensors I got from NAPA.

I was able to get Denso sensors (OEM for this truck) from NAPA. I installed those and after performing a couple of cold starts, the light went out!!

So, for those of you that are having similar issues, if you do not want to buy right from DELCO, you can get the sensors from NAPA. They are manufactured by Denso.

Thank you so much for everyone that chimed in to help me out. It is really appreciated!
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Re: Argh! SES Light Will NOT Go Out! *solved- Bosch sensor f

Post by F9K9 »

Glad to see that you worked it out. Bosch sensors sensors just don't work well for us. Non OEM fuel pumps is another area that you want to avoid. I know that you are pro NAPA but, everything changes with time. I can think of several NAPA sold products that were "golden" five years ago that have been altered or manufactured in a different country since then. Check out the distributor cap thread, when you have plenty of down time, and you can see how things have changed.

Check engine, MILs, SES, lights drive me nuts! Even if, you know it is something that is not damaging your rig or decreasing fuel consumption, something else can be hidden behind that light that has popped up since the last time you had it read.

My heep is throwing a code for "lose of efficiency" for one of the 2 precats and the OEM ones are on national back order. That's a real problem for members that have inspection laws in the states where they live (btw, it helps us to know where you live sometimes so, please take a moment and fill out your profile).

The point that I am trying to make is that you were correct in being irritated with the light. My light is something that I could correct with an aftermarket component but, at 110K, it is not hurting anything. I do own a "code reader" and I will read it a couple times a week to make sure that nothing else is hidden. Come tax return time, I'll throw $400 at the "black hole" and correct mine.
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Re: Argh! SES Light Will NOT Go Out! *solved- Bosch sensor f

Post by roadrunner »

I've been running Borg Warner O2 sensors on mine for a couple years now with no problems. My .02 worth.
2001 CC LS, pewter, stock, 4.3,Wait4meperformance, CFM throttle blade, Helix throttle body spacer, 4spd auto, 3button electric 4x4 shift, heavy duty factory suspension, Bilsteins, 1" rear wheel spacers, skid plates.
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Re: Argh! SES Light Will NOT Go Out! *solved- Bosch sensor f

Post by killian96ss »

And yet another Chevy that didn't like Bosch sensors. :roll: Stay away from Bosch sensors and spark plugs!

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Re: Argh! SES Light Will NOT Go Out! *solved- Bosch sensor f

Post by belstsrv »

Totally agree on the utter annoyance of the light! I am in PA and the light does need to be off in order to pass inspection so this was a major sticking point for me.

Regarding Napa, I am not so much pro Napa as I am pro-best price/value :) I am able to get parts there at cost so I always try to get them there, when possible. In this case the normally stocked replacement for my truck was not actually what they should be selling (Bosch). It is my understanding Napa is moving to actually sell the OEM manufacturer part for O2 sensors in the future to avoid this, but they are not there yet, hence me getting Bosch. If/when they go that route, people like us would (hopefully) get the Denso unit right out of the gate and save themselves lots of hassles.

I suppose the silver lining is this also forced me to do other routine maintenance that I had been slacking on like the tune up and so on. Too bad it came at the cost of so much aggravation too :)