Hey I have a 2002 RS and I have the engine light on --2 codes both sat O2 sensor low voltage---could it be that I have 2 O2 sensors that need replacement at the same time or could it be something else causing the Low Voltage on the O2 sensor? 2002 with 88,000 miles on it. Any advice or possible suggestions would be helpful--Thanks JIM

Let me guess--you went to Auto Zone and they read the codes? You could replace the sensors and hope for the best. They do fail. You could also find a good tech. and have it diagnosed and repair what is really needed. There are other things it could be, but without a scanner it will be hard to figure out.

pre or post cat o2 sensors...those cars have crappy cats, and could throw a faulty code of o2...

Chuck---you guessed it right--Auto Zone did the diagnosis--I was hoping to be able to change the O2 sensor myself and save some $. I may still do that but was wondering if there were any other common things to look for. dealer wants a ton of $ just to change the O2 sensors--I am going to buy some online and hope that cures the problem--After that if it doesn't clear up I may have to look for a good tech and spend some $. Car runs perfect and the light doesn't flash so I am hoping it's just something in the emissions. Thanks JIM

Always get the *code* from the Autozone guy, and not only his definition of the code. Some times their definition is too general (or incorrect) to diagnose the problem yourself.

the autozone scanners i`ve seen are generic global obd2 setups...that means they give a very vague discription of the code...they only give the code number of a manufacture code, and call it "undocumented code" which is just this side of useless...take the code number and post it...maybe we can give you the manufacture specific description for the number...

The code was P0137------------Oxygen sensor circuit, low voltage post convertor. I am just hoping a new sensor does the trick? he did not know if a bad sensor would throw this code. Thanks JIM

Could be a bad cat, a bad sensor, or a wiring problem in between. It's not complaining about a pre-cat sensor problem so I imagine the engine is running just fine. Doing a check of the plugs would help confirm it.

I'd swap the post convertor sensors (left / right) and clear the code. See if the code comes back up on the same side or not. If the same bank throws the code, then I'd carefully inspect the wiring, connector terminals for corrosion, etc. If that all checks good, you may in fact have a bad cat. If the code flips to the other bank, then the sensor is bad.

Dave, thanks for the info---I am going to change all 3 O2 sensors and them clear the code. Maybe this will solve it and I'm done. If not , i will seek some local help in trying to figure out if it's the CAT. or something in the wiring. I checked the wiring as best I could and all the connections seemed ok. Might have to pull them apart and check for corrosion if the code comes back. JIM

those 4 wire sensors arent cheap, and you could be replacing them for no good reason...thats the difference between a parts changer and a technition...(NO OFFENCE MEANT)a tech will take the time to replace only nessecary parts, and figure out why the part failed in the first place, so it doesnt happen again...dnult`s test is a good one, and doesnt take much time... you should atleast give it concideration...sometimes posted advice makes no sense at all, and i can understand bypassing those posts,but his is valid(sometimes, the stuff coming outta my mouth makes no sense to anyone...lmao...)not being dicky...just trying to help your wallet out...

I'm going to guess that 3 sensors is worth close to $300. Wouldn't it suck if it were just a bad wire? :clonk:

I really do appreciate the advice--that's why I posted the question here. I looked over the wiring today the best I could and I couldn't see anywhere where it might be broken--Tomorrow I am going to actually get under there and inspect the O 2 sensors and their connections. Maybe I can find something there. I have located the O2 sensors online for OE equipment it's about $150 for all 3--so I am first going to do the other inspections and then as a last hope go ahead and buy the 3 sensors---I have access to a scanner so that part is at least free.