O2 Sensor issue Please help!

[BOSSV6]

Well I hope this is not a repost, I searched for about 30min and found nothing exactly about this. If anyone knows a link about this please post!

Heres the issue...
The cars throwing code's alot if I use my codescanner and clear them they are back in a day or so. So its a reiccuring problem. When I scan the car I get 3 codes:

1. bank1 o2 sensor voltage high/low
2. bank2 o2 sensor voltage high/low
3. another o2 sensor code.
(I can post the EXACT trouble codes if it will help)

But basicly all the o2's are reading incorrect. I have the feeling this could be from alot of things. First off I have pacesetter headers & y-pipe. Also my EGR has been blocked off and I have a borla high-flow cat.

So im not sure if the car is actually running lean or rich or what. Ither way when I clear the codes and have the car running code free it has tons of power and runs great. But big surprize, once the Engine light comes on the car runs SLOWWW.

ANY HELP! would be great, but what do you think I need?
Replace the o2's?
Pick up o2 sims?
If replacing them is the way to go what are the best ones?

Thanks again everyone! like I said, if the exact codes are needed I have a scanner and can post em up. :)

[black98V6]

Re: O2 Sensor issue Please help!

ok, first question is what year is your car? do you have 3 or 4 o2 sensors?

Next you say you have pacesetter headers and y-pipe? I'm willing to bet you have some exhaust leaks. That is my first guess. And once the light comes on your car goes into limp mode to keep from cooking your engine.

check your egr blockoff plate for leaks.

That would be my first guess, somehow I doubt every o2 you have is bad unless you have other engine problems or damaged them.

On that note though a high flow cat could be causing a code for the after cat o2, personally for the after cat o2 I'd just get a sim, thunderracing.com has em.

I would also ask how long after the install of the pacesetters and new cat did you start getting o2 codes? Did you replace them when you put on the headers? reuse the old ones? if you reused them then you could have damaged or gotten something on them, silicone will do a number on an o2 sensor. If you used any type of silicone when installing the new headers your o2's are likely screwed.

hope this helps, without logging the o2 sensor readings you are gonna have a tough time at this, and with what our o2 sensors cost throwing parts at the problem is $$$$$$$

[BOSSV6]

Re: O2 Sensor issue Please help!

Thanks for the reply, first off I have a 96 3.8L

I know 100% I have exhaust leaks... my headers are actually broken I hit a large rock and I'm actually waiting for compensation from a construction contractor because it was construction debris that hit the y-pipe under my car.

But with that said I also know I had theese codes long before the headers were damaged. When I installed the headers the car was at a friends shop on a hoist.. and I was very carful around the o2's as I reused them.

After installing the headers only a few days later the moter started throwing codes, so its been ongoing for a while now.

Also the MAF is de-screened I dont know if that could effect anything with the O2's at all. (seemed like a good idea 2 years ago, then I started to read this forum)

I guess im going to wait and install my new headers and see if I can get all new O2's when I change them and see what happens. What o2's should I go for?


Any other ideas??? Thanks again!

[5_spd_pewter_v6]

Re: O2 Sensor issue Please help!

holy sh!t man, i have almost the exact same problems. check this thread where i explain the details:

http://forum.camarov6.com/showthread.php?t=75498

i don't know what happened either. my problems came up many miles after i had all this done, and i don't know why. i had the codes cleared about a day ago and they haven't come back on, but i don't know what the hell is up. please, somebody help with this

[BOSSV6]

Re: O2 Sensor issue Please help!

Sounds like your in the same boat as me!

Any other ideas guys? im still waiting on the City to compensate me so i can get a new set of pacesetters.

Also if you have one bad o2 and the cars computer goes into limp mode would the other 02's get bad readings and throw more codes?

[rdrr96]

Re: O2 Sensor issue Please help!

i recently installed my pacesetter's on my 96 camaro... i reused my old ones thinking theyd be fine but that wasnt the case... first my front left (in the header) went out... just basically stopped working, then the right side... then the one in my y-pipe went out, cleaning them didnt help, replacing them got the codes to go away but itll cost ya to replace them. all of them are easy to change, just gotta go get a "special" tool, attach it to your ratchet and disconnect the wires blah blah... its pretty self explanatory.

but anyways, just replace them. im guessing it had something to do with the fact that they are seeing A LOT more flow now that weve got those crappy log manifolds off. those pacesetters flow a whole hell of a lot better then stock manifolds. you can definately feel the change in mid-high RPM's for me.

[BOSSV6]

Re: O2 Sensor issue Please help!

i recently installed my pacesetter's on my 96 camaro... i reused my old ones thinking theyd be fine but that wasnt the case... first my front left (in the header) went out... just basically stopped working, then the right side... then the one in my y-pipe went out, cleaning them didnt help, replacing them got the codes to go away but itll cost ya to replace them. all of them are easy to change, just gotta go get a "special" tool, attach it to your ratchet and disconnect the wires blah blah... its pretty self explanatory.

but anyways, just replace them. im guessing it had something to do with the fact that they are seeing A LOT more flow now that weve got those crappy log manifolds off. those pacesetters flow a whole hell of a lot better then stock manifolds. you can definately feel the change in mid-high RPM's for me.

I have the feeling your right and that will fix the problem. Im still waiting on my compensation from the city here so i can get my new set! :D

Any other ideas?

[black98V6]

Re: O2 Sensor issue Please help!

yeah wait till you get your new headers then at least for the 2 o2's on the headers get GM replacements (ACDelco). Personally I'd stay away from Bosch.

[5_spd_pewter_v6]

Re: O2 Sensor issue Please help!

so if i replace the o2's it should fix the problem? you guys don't think that it will just eat up the next set i put in?

[BOSSV6]

Re: O2 Sensor issue Please help!

bump.

[black98V6]

Re: O2 Sensor issue Please help!

so if i replace the o2's it should fix the problem? you guys don't think that it will just eat up the next set i put in?

if you have other problems like exhaust leaks or some silicone in the wrong place then you will get bad readings from another set of 02's

Next assume that there are no issues with your o2's and they are working properly. This means that your engine is getting more air than it should or less fuel. More air means a leak somewhere in the intake via vaccum, intake gasket, or somewhere before the combustion chamber. You could also be getting extra air in on the exhaust side via leaks.

Next if you aren't getting too much air then you are getting enough fuel. Check your fuel pressure first. If you aren't getting extra air and your o2's are good with a good ground and such then you don't have enough fuel. This could be via bad fuel pressure or clogged injectors. If you truly are running lean you might be able to pull your plugs and see evidence of running lean.

just putting in new o2's will not fix the problem if you are getting too much air or too little fuel.