Originally Posted by rrich
It sounds like it's very lean, your rag test shows it.
Unplugging the upstream O2 sensor will help prove it - it'll run much richer unplugged.
I thought the O2 sensors were just for pollution monitoring purposes and there was a different sensor that controlled the air/fuel ratio that was connected to the throttle position sensor. Am I wrong?
I have random starting and idling problems and my check engine light was on for a day or 2 some months ago because of the O2 sensor...