My Check engine light came on during a smog check. Mechanic could not complete smog check due to low RPMs. Now light is off after being on for 5 days. What's the problem?
Check Engine Light ON/OFF on 2002 Ford Escape
Sometimes a oxygen sensor will intermittently give a bad reading then go back to normal, Have to put a scanner on it to see what turned on the check engine light
If you start throwing parts at a car without know what is wrong you can spend a thousand dollers and still not fix anything. The best thing to do is to have a shop put a scanner on it after the lite sets and they can look at freeze frame data to see what was happening at the time the code was set. It very well could be the o2 but at a hundred dollers a pop it is better to know. That is the biggest problem with todays cars. Alot of people will trust a back yard machanic to answer a question that he has no b answering. You can't fix a problem on what might be wrong, Trying to save money trying to fix a check engin lite can cost a fortune. Takeing your car to a shop to get it fixed may seem high, but in the long run it isn't realy. What some people do is take it in and have it diognosed and then do the repair youself. BUT do not let someone just read your code THAT IS NOT A DIOGNOSES. If a code is for cat ef that doesn't mean you should go out and buy a cat.