Im out of ideas. Please help ID my O2 problem

[wcj]

Im out of ideas.

Ive swapped injectors. Swapped O2 sensors. Swapped O2 sensors between banks. Swapped battery. Can anyone give me an idea what is causing my bank 1 O2 to spaz out like this? It does this even when I swap sensors.

As you can see, when it freaks out, it causes the car to run pig rich on that side.

[Wheelz]

If its not tracking with any sensors or injectors it could be wiring.. Which isn't going to be easy to debug

[ddnspider]

It looks like your wideband pid is also tracking a goofy A/F and bouncing around so the narrow band may actually be correct for that bank. Have you gone open loop and logged your A/F with the wideband?

[joecar]

HO2S11:
to the right of your cursor it looks like HO2S11 sees too much fuel...
what happens if you swap injectors across banks...?

What DTC's do you have...?

[wcj]

Have not tested in OL.

Hey Joe, Nothing changes when I swap injectors. I pulled my FAST36 injectors and replaced them with stock Z06 injectors (adjusted BIN) and the O2 still freaks out. I get no DTCs...

The car does run normal at times so this problem is sporadic.



Do you think a weak exhaust valve spring could cause this? Maybe a vacuum leak on the driver-side of the intake manifold? When the O2 freaks out, the bank1 injector duty cycle does increase so the computer is dumping fuel when this happens.

[joecar]

If it was an airleak on bank1, then O2 sensor would see extra air and voltage would peg low...

but, O2 sensor is pegging high, meaning that it sees less air on that bank (more fuel, or clogged header primary/secondary).


Check injector sub-harness, it might be crimped or chaffed (allowing it to sometimes short to ground, firing several injectors).

[joecar]

But... that is really weird, why is IBPW1 is running so much higher than IBPW2...


can you also log LTFT's.

[wcj]

Ltft is disabled.

Clogged cat? Even if I have an x-pipe? That wouldn't cause the computer to adjust bank1 injectors, would it?

[joecar]

Ltft is disabled.

Clogged cat? Even if I have an x-pipe? That wouldn't cause the computer to adjust bank1 injectors, would it?

No, forget the clogged cat, that was before I decided that this was weird


Are STFT enabled...?

[wcj]

Yeah. I can try to log some STFTs. May take me a few days to get to it since summer's been crazy. Would it help if I attached the previous logged file? Dont think this could be valve-train related? Bad PCM?