I bought my son a 87 3L 4WD V6 pathfinder. It has a worn out exhaust system.I'm not much of a mechanic, but my son and I are going to try and do the job ourselves. My question is, Should I change the catalytic converter while I'm at it? I don't know how to tell if one is bad. The other question. There is a sensor screwed in the pipe just pass the converter. The wire goes toward the hood, to the passenger side of the car, and plugs in. If that is the oxygen sensor,should I go ahead and change that also? The Pathfinder has well over 200,000 miles on it.
If it isn't broke, don't fix it.