I had my y-pipe installed by a shop maybe 8-10 weeks ago. It was a used pipe and the flex is bad so I'll be replacing it, but besides that, everything was fine. Then suddenly yesterday the CEL went off. I pulled the code and got 0509, which is the front O2 sensors on the pipe. I reset the CEL so now its off. My question is if the O2 sensor really is bad will the CEL go off again, or will it stay off now cause I reset it? If the O2 sensor really is bad is my car running differently?

shaz

 

if the 02 sensor is bad you are running extremly rich. O2 sensors are very delicate.. and i would say about 45% of y pipe installs result in a broken 02 sensors. Nigel (turbo97se) sprayed brake cleaner on his 02 sensor to revive it, don't know if that will work for you.

 

But how would I know if I had "revived" it or not. I'm willing to replace the sensor...I just need to know if its really actually bad, will the CEL trip again?

shaz

 

Come on guys, i really need advice here. If the O2 sensor really is bad, will the CEL trip again now that I've reset it?

shaz

 

I'm waiting for an answer also. I reset my CEL the other day and am anxious to see if the code reappears. My 97SE has no mods -- I ran a bottle of injector cleaner (some powerful stuff) through the tank and the result(?) was an 03-03. I reset hoping that the CEL does not relight....and the O2 is NOT bad. Another factor: I received a different diagnosis from AutoZone's check of the code than I did with "self-diagnosis". Question is: Which diagnosis is correct? Hopefully none of 'em. I'll be watching gas mileage diligently.

 

If the O2 sensor is bad, your CEL will come back on. If your somewhat mechanically inclined, you can do the repair yourself. Stay clear of any stealership.

 

The online-chilton manual gives a DIY testing procedure. Maybe this can take the guess work out of everything.

http://www.cybrrpartspro.com/Chilton...61CH04_15.html

 

If you get another code, pull the sensor and clean it with a rag lightly soaked in a solvent(brake cleaner is cool). Dont drown the sensor, just wipe all the black soot off it. If it still trips, If you get a code more than a half dozen times I'd say replace sensor.


railmax97 - The DIY self diagnosis is correct. So long as you interpreted the flashes correctly to arrive at 0303.

 

Well its been 2 days and my CEL hasnt come on again. Im getting my new pipe installed in a week or two...think I should replace that O2 sensor just to be safe?

shaz

 

Hmmmmmmmm

 

if your O2 sensor is bad. MAN!!!!!!!!! you will see after a few days your gas mileage will kill you. Check the O2 ASAP with haynes or chilton manual instructions.

 

if its not bad.. don't replace it

 

Prior to my SC install, my O2 sensor went bad twice. It went bd, I and gave a CEL. I took it, said "uh oh" and reset it. After being reset, it stayed off for about 2-3 weeks. 2 weeks prior to my SC, it came on, and stayed on, despite multiple resets. I changed it out during the install and it's been fine since. I think if it gave you a CEL, it might be starting to go bad. But like Sprint said, if it ain't broke right now... don't fix it Give it a month and see if it comes back.