- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
Those cars are notorious for engine problems unfortunately. The exhaust valves tend to warp from heat after around 200k miles. Therefore throwing the O2 codes. Best outcome and cost effective thing I can recommend is replacing the engine with a new or low mileage engine.
I would say 10 to 20 miles would be enough to tell if the trouble codes will return. You may be able to disconnect the battery for a couple of hours to clear the codes, but using a scanner or code reader is better. A scanner or code reader can find history trouble codes on some models and in some cases without the engine light being on. The purpose of the warning light is to tell the driver the vehicle needs attention now.
200 miles is more than enough. p0420 is a cat code meaning the cat in the exhaust is not doing its job. you need to make sure there are no exhaust leaks before the downstream (last one) o2 sensor. if you can get all but 1 monitor to set without the check eng light coming on, you will pass pa emmissions.
with a hand held diagnostic computer it can be done in about an hour. Drive the car as an owner it could take up to a month. It is the driving condition , not mileage that resets the ECM. You have to drive on the highway at certain speeds for a certain amount of time, then in city driving, stop and go and at certain speeds for so long. The computer guides you threw it. If you only drive city or highway you may never get it to reset.
Let's see if I got this right.The vehicle can't be driven because of legal issues with the emissions test, and it has to be driven 200 miles before it can be tested. Talk about your catch 22. Jack that thing up, put it on jack stands, fire it up, put it in gear, and watch the miles add up.
just a word of advice there is no sensor that tells you if you need a cat ! that code comes on because of faulty o2 sensors have you changed the 02 sensors yet ? if not change them reset ( clear ) the codes that code will come on a few times just keep resetting or clearing it i have had 2 co workers not listen to me and changed the cat 400-600 dollars and the code just comes back on one guy had the cat changed two times and the code came back after i reset the codes 3 times it stayed off it seems like its preset to come on around 100,000 miles with 02 sensor codes DONT LET THE MECHANIC SELL YOU A CAT hope this helps
it could be that the wiring to or from the knock sensor has a prob. also after the knock sensor was changed was the code cleared? if it was not it may be a inactive code that stays in the computer causing the light to stay on...