I went to Advanced and got an ODB reading for my check engine light, and the numbers didnt match anything in the Haynes Manual. They said it was fuel-mixture related and blamed it on the O2 sensor, which has also been mentioned by others i've talked to. The light has been on for about three months, came right back on even after i changed the almost totally useless fuel pump and reset the computer. Didnt notice much of a problem in performance, the occasional stalling at a stoplight but that's about it. Well the last couple of days it has been running ROUGH, i'll be driving along and it will act smothered and slow down, then suddenly kick back in and run fine for a mile or so before doing it again. In fact it acts much like the fuel pump problem, except this time there isnt the incessant backfiring sound. Also it has been burning significant oil. So today i decided to try and check the O2 sensors, i cant get the one by the manifold to break loose but i checked the one below the Catalytic converter and it had some corrosion and/or crap on the rounded tip that carb. cleaner wouldnt take off. (i can post a picture if it will help)

SO if you have any advice about any of that, it would be appreciated. Also, does anyone know what a good O2 sensor looks like, and can the function of a sensor be determined by it's appearance. And lastly, does that bottom sensor even matter all that much, would it affect performance?

thanks for any help.

 

Okay, whats the code from the OBD scaner?
O2 sensor is a good guess, You really can't see if they're bad.
But if its all gunck up then it just might be, but what cuasing that? is your problem
I've found that once all the sensor are good. A new MAF and good injector cleaning job really does the trick.
As for the O2 behind the cat. its signal trails the one in front and lets the computer know it working.

 

Yea they have changed the codes a few times , So you gotta have the rite book for your system , Should tell you on the lil tune up sticker thats under the hood what system you got, EECIV, EEC V , etc like that , thers 2 , 3 , digit codes an the newer ones have letters in front of them , The newer ones are an attempt to give a standard across the manufactors, So you dont need a differnt scanner to work on diff vechiles and things have the same names , Use to be each company had a differnt name for the same kind of componet, very confusing, An yes both 02 sensors work together. , An to be honest with you you cant guess on replacing sensors it can get very costly.