sgtD

my camaro runs decent when its cold but once it warms up it runs like *** at lower speeds but once i get on it its alil better. it sounds horrible too. I jus had it tuned and replaced the opti but neither fixed the issue. any suggestions

LS6427

iTrader: (2)

You talking like just a couple minutes after start-up....it runs rough? Then when you get into the throttle pedal it clears up some?

If so....I'd say you have an 02 sensor on its way out. Get a scan....

.

sgtD

it doesnt clear up. once the car is warm it starts runnin rough and continues as long as im goin about 30mph or slower. when i accelerate it dont jus go it kinda builds up the shoots off. if im on the gas goin over about 50mph its alil better. i replaced the o2 sensors and plugs on friday before i got it tuned. i had the opti replaced today and still running rough.

firebirddude98

check your fuel pressure, could be your pump or regulator or something in that nature

firebirddude98

or EGR, i guess that could do like that when it's warmed up, or maybe even your cats might be blocked, i would think the cats would do like that more cold than hot though, never know

sgtD

this is it. you can hear how nasty it sounds. i got new opti, coil, o2 sensors, no egr or cats.

http://www.youtube.com/watch?v=4j3Re...jruSLAd5ABgDii

LS6427

iTrader: (2)

Could be a nasty clog in the fuel filter, then when pressure gets up high enough to overcome it, it takes off. I'd try changing it, even if its been changed recently.

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sgtD

its at the shop now they said they cant find out what the problem is

xny1989

iTrader: (1)

Kinda sounds like a misfire to me. I'd check all the plug wires to make sure they're on tight, and make sure the plugs are tightened up, especially #8.

sgtD

i took it to a different shop today and they said they couldnt find the problem. they said they checked fuel pressure and the injectors. i paid a lil closer attention on the drive home. it rides decent for a few minutes the gets real rough. i pulled over turned it off then started it right back up and it was back to runnin fine for a few minutes till i got home. so its not an issue of it warming up then goin to $hit.

lt1pwr1

iTrader: (1)

First of all, let's back up a little.

Why did you have it tuned in the first place? Did you just put some mods on the car? Who tuned it and did it start acting up right after the tune?

You say you replaced the opti, so assuming this is pre 98? What year is it?

It is hard to tell in the video but that sounds like a major (constant) misfire or a bad exhaust leak. Since you have no flashing SES I'm assuming a bad exhaust leak but I can't see how a shop would not notice that.

Lastly, did the shop see if the o2 sensors were switching properly? It sounds like maybe the shops just don't want to deal with it.

LS6427

iTrader: (2)

Once again.....get a scan......like mentioned......check to see if the 02 sensors are switching properly. This sounds like the exact symptoms of failing 02's. And NO....you will NOT always get a code till things get really bad.

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sgtD

its a 94z28. i got a cc306 cam 1.6rr 36lbs injectors 58mm intake and tb lt headers and all the other bolt on stuff. it needed a tune.i replaced the plugs and o2 sensors before i got it tuned. the shop i been takin it to is a performance shop that deals with camaro and mustangs. they said it was givin a code for the opti and a low engine temp (temp sensor for the computer wasnt hooked up only for the aftermarket gauge) i replacedthe opti, that aint fix it so i took it to a different shop for another opinion and they couldnt find anything. im certain its not an exhaust leak. its gotta b a misfire but idk whats causing it. the usual suspects are good. im gonna unhook the o2 sensors and see what it does.

sgtD

it was an o2 sensor. i unpluged the passenger side sensor and now everything is fine. the sensor is brand new so idk why it cause a problem. and now that i think about it. i had only been runnin 1 seonsor and when i changed them out for the dyno i hooked both up and that when it startted acting funny but i didnt think that couldnt made that big of a problem. but it runnin like a champ now. im probably gonna jus leave it unplugged

LS6427

iTrader: (2)

Told ya........that was classic 02 sensor symptoms. When you run sluggish its dumping fuel......when you hit the gas you let more air in and it gets leaner and "appears" to run better in that rpm range.

But.....you're PCM might be running in a default SD tune.....if that year PCM can do that. You should find the issue........then fix it.

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lt1pwr1

iTrader: (1)

Probably one of two reasons the new o2 failed. One, headers can trash out o2 sensors so it probably ruined the new one after you installed headers.

Or two, you put an aftermarket o2 like Bosch instead of Denso's or Delco's and it was bad to begin with. Anyways, glad it's a non-issue now