Replace both the upstream ones at the same time so the reading will be consistent. You can keep the downstream one on there. The only difference between the two is the length of the wire. You can also ...

Anyone have experience with this? The dealer quoted me (1 hour of labor minimum) about $400 total (with parts).Figured I could do it myself for 1/2 that. Replacement sensors run about $120 (for all 3) ...

I have a Ford Ka 2003, just under 60,000 miles with the Check Engine light on. Went to garage yesterday for diagnostic and they said that it was an exhaust sensor issue and the light had gone off but ...