service engine soon light

[tom3]

Wierdest thing I've heard in a while. Unless I'm mistaken the fuel pressure is regulated at the fuel injector assy so the pump is not an issue unless it was a low pressure pump, not likely. Are these three wire O2 sensors? Getting power to them? Check fuses?

[hills6]

The sensors have four wires. Which wire should I expect to have voltage on it? If I remember what I've read on other posts that is a very low voltage, like a few hundred millivolts, yes?

[BlazerLT]

I just did some research on your problem and the bank sensors reading rich is usually due to a MAF sensor going bad.

Have you descreened your MAF or installed a new K&N filter lately?

[hills6]

No, I havent owned the vehicle for long. It looks like I need to go & pick up a service manual as I couldnt tell you about either one of those things you mentioned. I know what MAF stands for but thats about it.

[BlazerLT]

Yea, get a Chilton AND a Haynes manual.

Total cost $30 and well worth it.

Go to the wrecking yard and get another MAF sensor and see if it works.

Also, unplug the MAF and see if the engine runs worse or not.