o2 Sensor Data

[tatasta]

I did some mods to my car which included LTs. When I went to headers, I ruined an o2 sensor that was stuck in the stock exhaust. I bought a new one that was supposed to match the previous sensor. But since then, my fuel trims and idle are not good. Please take a look at the screenshot. Should my o2 voltages look like that?

Thank you

[tatasta]

I guess to be more clear, both sensors oscillate from 6 volts to around 250 volts. Cycling up and down and often they are opposite of each other.

At operating temp on the engine, should they not be closer to even? Is it possible that they are mismatched sensors? I will also check again for any vacuum leaks.

Never logged o2 data before. Just curious what it should look like.

Thank you

[Jayjellyfish212]

Try the tuner section..you’ll probably get more traffic to your questions there. There is also a few tuners in there answering questions like yours.

[InFiD3ViL]

Originally Posted by tatasta

I guess to be more clear, both sensors oscillate from 6 volts to around 250 volts. Cycling up and down and often they are opposite of each other.

At operating temp on the engine, should they not be closer to even? Is it possible that they are mismatched sensors? I will also check again for any vacuum leaks.

Never logged o2 data before. Just curious what it should look like.

Thank you

This is how mine behave, independently of each other.

But for voltages, a normal sensor should be operating anywhere from around 100 mV - 900mV, with 450mV being Stoich. Optimal is 350-650mV. Lower than 450mV is lean, higher is rich.

When my passenger side sensor died, it wouldn't get above 100mV and would barely cycle.

I am not sure if since you are Supercharged if that requires a different model sensor, but these are the OEM sensors I always replace with, and ALWAYS in pairs. They are the exact sensors a 2010 Camaro SS comes with from factory. I don't run cats on my car, so I just want to make sure I'm talking about the correct position:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Otherwise, I would go to the tuner section as said above or hit up your tuner himself. There are some super smart guys here that should be able to point you in the right direction.

[Avenging Orange]

Has the car been tuned?

[Pro-tuned]

It’s obvious your tuning with SCT X4. It appears there is misfire from cylinder 8. The sensors should be reading nearly the same. The front sensors are different than the rear and carry a different part number. As you have LTH your rear sensors are turned off in the tune so don’t bother with them. If your sensors are identical and in the proper position then you may have an exhaust or vacuum leak or an electrical wiring issue. I would recommend you add fire insulation over the harness extensions for the sensors which is a common problem. Definitely something is not right.

[tatasta]

Originally Posted by Pro-tuned

It’s obvious your tuning with SCT X4. It appears there is misfire from cylinder 8. The sensors should be reading nearly the same. The front sensors are different than the rear and carry a different part number. As you have LTH your rear sensors are turned off in the tune so don’t bother with them. If your sensors are identical and in the proper position then you may have an exhaust or vacuum leak or an electrical wiring issue. I would recommend you add fire insulation over the harness extensions for the sensors which is a common problem. Definitely something is not right.

Thank you for the reply. Initially the car was remote tuned through the SCT. However, when I added headers, I took the car to a tuner in Salt Lake City that did the header install and a dyno tune with HP Tuners. In the time that I had alotted with the tuner, they were not able to identify the issue. I am currently just logging with the SCT. The misfires on #8 popped up in one big spike. Then I did not see any other misfires in a log that was about 14 minutes. Drove the car yesterday and while cruising or doing a bit of WOT, the fuel trims and AFR look good. It is this stubborn rough idle that I am dealing with that is driving me crazy. I removed and put new gaskets and o ring on the supercharger and manifold with a lot of care to keep it sealed. Went around every vacuum point with starting fluid and unlit propane torch and cannot get a response that points me to a vacuum leak.
This issue was present before the header install and I had hoped that if there was an exhaust leak, putting new American Racing headers and new gaskets would remedy that. Still the same.
The issue started when I added, from the standard SLP kit, a smaller pulley, ZL1 pump and controller, ID 1050s, new tensioner and catless mid-pipes. Which is when I stripped out one of the stock front o2 sensors. I did (I believe) get the correct sensor. Switching them side to side does not make a difference.

If it is possible to get some insight on what exactly what to log to look for the issue, that would be great.

Thank you

[tatasta]

Originally Posted by InFiD3ViL

This is how mine behave, independently of each other.

But for voltages, a normal sensor should be operating anywhere from around 100 mV - 900mV, with 450mV being Stoich. Optimal is 350-650mV. Lower than 450mV is lean, higher is rich.

When my passenger side sensor died, it wouldn't get above 100mV and would barely cycle.

I am not sure if since you are Supercharged if that requires a different model sensor, but these are the OEM sensors I always replace with, and ALWAYS in pairs. They are the exact sensors a 2010 Camaro SS comes with from factory. I don't run cats on my car, so I just want to make sure I'm talking about the correct position:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Otherwise, I would go to the tuner section as said above or hit up your tuner himself. There are some super smart guys here that should be able to point you in the right direction.

This is the sensor that I bought to replace the damaged one. It matches (in appearance) the stock sensor that is in the other side.

[Pro-tuned]

I don’t believe your 02 sensor is the issue since you changed sides and the problem didn’t follow. I would return the car to stock and use the SCTX4. Also ensure you have the latest updates for both the device and the software. Get with Jannetty and get his tune, he has done this package many times. He is supportive and can help you resolve these issues. Platforms for HP Tuners and SCT are different and require special processing to transfer between platforms for the first time. I can’t comment that the transitions were done correctly. I would however stick with a single reliable tuner.

[tatasta]

Originally Posted by Pro-tuned

I don’t believe your 02 sensor is the issue since you changed sides and the problem didn’t follow. I would return the car to stock and use the SCTX4. Also ensure you have the latest updates for both the device and the software. Get with Jannetty and get his tune, he has done this package many times. He is supportive and can help you resolve these issues. Platforms for HP Tuners and SCT are different and require special processing to transfer between platforms for the first time. I can’t comment that the transitions were done correctly. I would however stick with a single reliable tuner.

Thank you.

Ted did the original tunes for the car. As mentioned, the issue did not begin until I added the cat less mids, fuel pump/FPCM and injectors. It was Ted who recognized the issue first through uneven LTFTs. His tune before these mods was spot on. Ever since, I have done smoke testing, resealing, etc. to track it down. When I had the headers installed and dyno tune done at JDP, the problem was there before their tune. I log the same LTFT data as I did when Ted's tune was in the car. I just recently logged the o2 sensors for the first time and they just don't appear to be correct.

On the o2 sensors, both sides are currently oscillating from 10 - 250 volts in regular cycles at idle. Very seldom are they somewhat close to each other.

Is there any value, since I do not have a tuner near me, to having the local dealership try to diagnose the car? If it is electrical, I am screwed. I am no good with electrical...

Thanks again!

[PepeLePew]

hey tatasta - this is a frustrating one for you for sure. Sometimes diagnosing gremlins like this can take a long time. I know it's a long shot, but you might want to double check that your wiring harness on the passenger side is not touching your headers. I just had this happen to me and had all sorts of electrical problems popping up after about 500-1000 miles with my headers. I then noticed the harness was barely touching the header tube on number 8 and when I unwrapped the harness, I noticed most of the wires were melted together and several were damaged. When I pulled the wires apart, I damaged even more of them. Needless to say, I spent 3 days splicing 12 wires in and soldering 23 connections. I also had a blown MAF fuse as a result that I had to replace. Good luck and let us know what you find.

[Pro-tuned]

As you have said in so many words concentrate on the side that is off. No tuner can fix imbalance of LTFT and the car run correctly, this is not a tune issue, so don’t let any tuner mask this issue either. Knowing Ted he will not tune your car further till the issue is resolved, that’s why he is one of the best in the business.

Your absolutely sure you have no exhaust or vacuumed leak, checked all plugs on that side to include plug wires and coils? As stated above twice, I would also remove the header extension harness and have it checked if you don’t know how to test it for continuity take it to a friend and let him check it. This is a common problem as I mentioned above. I have heat insulation on both sides of mine.

Your getting there just keep hunting...

[tatasta]

Update: I took my car to the dealership to have it diagnosed. I know the tech there and he is very good. He spent several hours on my car (and only charged me for two). He found no vacuum or exhaust leaks. Confirmed that the trouble cylinder is #3. Ohm and load tested all associated wiring. What he did find was an underlying code (which did not trigger a CEL on the dash). He could see that there is low voltage to the #3 coil. He said that is not a true misfire. Basically, a "soft" misfire that is intermittent only happens at idle. No issues when actually driving. Possibly incomplete combustion??
Any way, he recommended changing the ECM. However, my tuner has already done that. Changing the ECM made no change.
So, my question is: If my parts and wiring are all good. Is it possible that there is an issue within the tune that was simply carried over to the new PCM?
The issue first started when I installed new injectors, a 3.2 pulley, ZL1 pump and FPCM. And a revised tune for the new parts.
Any thoughts?

Thank you for reading.

[xc_SS/RS]

Did he or you try moving the #3 coil pack to a different cylinder to see if the problem stayed, or followed the #3 coil pack?