I'm wondering if I can get away with only replacing the upstream or pre-cat sensors. My Suburban has 4, and is not experiencing any problems, except for lower fuel milage. I've read about the sensors and everything is telling me that the two upstream sensors are used to adjust fuel mixture, while the downstream ones measure the effectiveness of the Cat. Is it ok just to replace the upstream sensors? What problems might this cause?
Oct 13, 2008 at 1:36 PM
