[vasillalov]

Hey folks,

I've recently started seeing O2 codes appearing out of nowhere. This is accompanied by somewhat rough idle and a few misfires here and there. There have been zero drivetrain changes in the last year as I've been working on suspension and brakes.

Here is what I am getting rather frequently:

2C7E Lambda probe behind catalytic converter, trimming control
Error will cause a warning light
Error is not currently present
Test conditions have been completed
Signal or value below threshold

Freeze Frame Information
Event 1Odometer 66688kms 41438miles
voltage Lambda probe behind catalytic converter bank 1 0.06 V
voltage Lambda probe in front of catalytic converter bank 1 1.80 V
Lambda shifting return valve 1 0.00 -
input signal return valve 1 0.00 V


2C6C Lambda probe behind catalytic converter 2, system check
Error will cause a warning light
Error is not currently present
Test conditions have been completed

Freeze Frame Information
Event 1Odometer 66688kms 41438miles
voltage Lambda probe in front of catalytic converter bank 2 1.58 V
resistor Lambda probe behind catalytic converter bank 2 1,792.00 ohm
Engine speed 3,040.00 rpm
voltage Lambda probe behind catalytic converter bank 2 0.63 V



I recently had to install the DP Fix to pass emissions and I am wondering if I somehow mixed the signals from the O2 sensors.

Any suggestions and ideas?

[vasillalov]

UPDATE:
The logging did not reveal anything out of the ordinary. So I took my car to the track, aka "The Proving Ground" and after two solid sessions of 20 minutes each I was finally able to break something.

On the third session the car misfired, thew a bunch of CELs and I brought her into the pits. Quick scan revealed that I had a misfire on cylinder #5 . This is what I've been waiting on for a long time. The fuel injector on #5 cylinder was the last one that I was waiting to fail before I replace it with the updated gen 2 injectors (261-11). The injector was leaking so badly, that my car threw an "O2 muddled" error code. Yet, there was no misfire till yesterday.

Long story short: I put in a brand new injector, coded it in and the car runs smooth as butter right now. No more idle misfires during cold start, no more O2 CEL, nothing.

So I guess this could serve as a good example of a case where a bad injector was causing O2-related CEL but yet no misfires. I have not followed up with the recent developments in the piggy back tunes, but I suspect this sort of thing would have been unnoticed for a long long time if CAN-clear functionality is ON in a piggy.