Originally Posted by Arne2 (Post 6897176)

My 3.2 does this, but only on cold start. Will settle to normal idle after 15-20 seconds. Never does it warm. PO replaced the O2 sensor a few months (read as a couple hundred miles) before I bought the car. Since it never does it warm, I'm assuming that it's not a vacuum leak. I suppose the new O2 sensor (correct Bosch) could be bad, maybe contaminated during install. Haven't dug into it in depth yet.

Originally Posted by PabloX (Post 6897277)

My understanding is that the O2 sensor does not come into play until the car is warm. So, I think you need to look at other solutions.

Originally Posted by Arne2 (Post 6897424)

Good info. I'll keep that in mind when I dig into this. Looks like I need to look at the differences (air paths and such) during cold running.