More on check engine light.

[svtwill]

I saw that there was a post for a 91 with a check engine light problem. Mine came on and stayed on last night. Is this a simple fix? Can I just change the 02 sensor? I just don't really want to take it in.

Help!

 

[TPLYNCH]

Welcome to the site. If you run a search for check engine light, you will find a vast # of threads related to this. Unfortunately, any number of things can cause a CEL, from as simple as not having a gas cap on properly to any # of failing sensors. You can see the miriad of parts that people replace trying to get rid of the CEL. If it is the O2 sensor, what caused it to go bad? Fuel Pressure Regualtor dumping to much gas?? Old age?

My suggestion would be to go and by a code reader at your local parts outlet. They are pretty cheap for pre-OBD-II engines and read the codes and find out what it is your engine is trying to tell you. If you search for code readers, you'll find lots of info on them too.

Guess what I'm trying to say is it just may not be as simple as a bad O2.

Good luck!

Sorry, thought yours was a '91. You have the OBD-II which is very expensive to by a reader for.

 

[Explorer7012]

I have an '96 Explorer Sport 4X4, 5spd and my check engine light came on also. I had the codes downloaded because I thought maybe I could fix the problem myself instead of taking it to a shop. I got two codes: P0401 and P0420. I looked them up in my Explorer manual and I had no idea what they really meant or what the problem could be. I ended up taking it to a shop and they got the exact same codes and all they ended up doing was replacing the rear O2 sensor! A $200 job!!That fixed the CEL problem, but I don't understand why I got those two crazy codes when the only thing wrong was my O2 sensor??!!