Bad cat or rear 02 sensor? It says, "low threshold in catalyst". How would I go about fixing this long enough to get by inspection.
Quote, originally posted by Blackonwhite99r6 » oh okay, awesome. I will check it for leaks since the engine light was cleared, then it came back on for a day then it turned back off. I dont know really what to think
If the cat is bad, then the code will come back, but sometimes it takes a few days, as the readiness code for the rear sensor might require several heating-cooling cycles to either set or fail to set. Cats don't really leak when they fail (not sure what you mean by the first part of your post), but they do become clogged with time, and lose the ability to clean up exhaust emissions.
Post up some info about your car (model, year, mileage, maintenance history, etc...).
its a 98 jetta with 135 thousand miles, I think the maintenance was lax because I had to replace a lot of stuff when I picked it up. The engine light was on when I got it and I put a new exhaust on and the engine light shut off for a little while and then came back on. Then it stayed on. I got it scanned and cleared a week ago and it stayed off for a day and a half, then came back on for a day, then shut off for half a day, then came back on again and its still on.