Deenasty

Just as stated, Bank 1 STerm Count goes to 150, while the LTerm stays at 130 at idle.

Bank 2 everything is fine Sterm Count 128, and LTerm Count 128.

This is only occuring at idle, with an idle PE tune. My lm-1 is on bank 1, after the o2, and it is reading 13.8 at idle. What can cause the STerm to be reading so high? There are no exhaust leaks present. Please help!

Injuneer

How often does the short term go to 150? It's changing 9 times a second, and its going to be all over the place. The important thing is that the average value over an extended period of time is 128. If it isn't 128 average, it should cause the long term to move upwards, so that the shrot term will average 128. That's the whole basis for "learning". If it is staying at 150 for an extended period of time, and the long term is not changing in response, learning may be disabled.

Deenasty

Yes learning is disabled. Its idleing in PE. Bank 1 Sterm basically keeps going up until it hits 150 and remains there. The LTerms though do not move from 130. We went with a Idle PE because of the camshaft size.

Injuneer

If learning is disabled, the LT's will not change. That's what "learning is". You need to find out why the PCM thinks that side is running lean. Since it can't correct by adjusting the LT's, its pushing the ST's high enough to make the correction.

Deenasty

ahhhhhh..It all makes sense now. Now Fred, what should I look for, that could be causing that side to think its running lean?

Injuneer

The usual suspects... exhaust leaks before the O2 sensors, something externally affecting the O2 sensor (contamination, oil drip, exhaust leak nearby), misfires and or failing O2 sensor or wiring problem on that side. Swap the O2 sensors side to side to see if the high ST's follow the sensor, or stay on Bank 1.

Deenasty

UPDATE: Now something really weird is going on. I told you guys that I was having a problem with my Bank 1 STerm's going reallly high. So I swapped o2's from side to side, and now the problem has moved from bank 1 to bank 2. I changed the o2, with a brand new one, and the problem is still there. I dont know what to do now. It seems that with every different file I load into the car, the STerm Blms are different everytime. Now the problem only lies on bank2, (keep in mind the lm-1 wideband is on bank 1) Although bank 1 both STerms and LTerms are staying at 128, the car is still running pig rich (11.8-12.2). I emailed my tuner, Bryan at PCMFORLESS, and he states there is nothing he can do now without having the car in person. Now what am I suppose to do?

Injuneer

Did you reset the PCM when you swapped the sensors side to side? It makes no sense, if learning is disabled, that the LT's on Bank 1 would have suddenly changed from 130 top 128. The only way that could happen is if you reset the PCM, and if the BLM's aren't locked.

Deenasty

I have not reset the PCM...should I just pull power from it for a while? The BLM's are locked..

GMRL

Dont know if this would help any, but I was having problems with my bank 2 sensor 1. I kept getting a no activity, heater malfunction codes. After a lot of digging, and inspecting harness, and sensors. I checked my o2 extensions from casper electronics. 2 of the wires were crossed, so I switched em around. Dont know what kind of extensions your using, buts its worth a check I guess.