Thread: Pending fault code for low O2 before engine is even started? (05')

I have noticed that if I connect to Tapp with the ignition on and wait until the car and phone are reading that after several minutes I will get a pending fault code for Low O2 sensor fault without the engine started. The PCM must be smart enough to know if the engine is running or not and if the O2 is up to temp and switching. You would figure there would be a delay or something. I have the app telling me about pending fault codes and when the engine is up to temp. Also when I log I typically wait until everything is reading, start logging then start the car.

Jeff

If I start the car and let it run for several minutes it won't do it, but the code comes back as 2-4 minutes (to occour) which is almost the time it takes to link and then the output is low, until the O2 starts switching. I'm just wondering if this is one more telltale sign someone is a hack. I've been thinking about contacting the previous owner and asking if they have any info they can get me.


Jeff

Have the same issue is the code a p0171? I have to replace my 02 sensor soon as well...

Only if I try to go full throttle, then the engine lays over dead lean and timing can be as low as 15* ATDC (not before) (I also get a P0068). I think we've narrowed it down to a bad tune on the PCM.

Jeff