Hi bj porter,
Thank you for the donation.
Yes, a failed O2 sensor can cause bad idling and very poor mileage.
However I would suggest checking the spark plugs as well.
I would like to know the exact error code that you got for the the O2 sensor. Sometimes the O2 sensor shows a code because of other influences, eg, running lean or rich
Thursday, December 4th, 2008 AT 6:53 AM