808cruise

Should I change the o2 sensor or the catalytic converter?

Yeret

I used to get this code incessantly in my Ram (the downstream, not the upstream sensor thank goodness). Using my code scanner's live display, said sensor is stuck at 1.0 volt ouput and doesn't fluctuate like it should while the engine is running. Since the computer simply useses this particular O2 sensor to verify the catalytic converter is working and doesn't adjust the fuel/air mixture with it, I never bothered with it. Of course a couple weeks ago my catalytic converter plugged...

Check eBay or Rock Auto. O2 sensors aren't very expensive and can save you a lot of hassle. If the exhaust is old, however, don't expect them to come out easy...

Now, verifying that the catalytic is bad, from my 2 experiences, is as simple as driving the car, realizing you have no power no matter how much gas you give it, no check engine lights and even if you floor it in park, the engine doesn't rev past a few thousand RPMs. If you're lucky, the engine won't vapor lock on you...