I'm sure this has been posted many times but I couldnt find it.

Misfires at idle, jerks at light throttle and very noticeable power loss in upper RPM (4000+)

Has a CEL. "lean pistons"

Also blows black smoke from time to time for what I hear from my friends when I go WOT.

Now my guess might be a bad o2 but i'm not sure. Just want a second opinion..

Thanks guy.

-Mike

 

can you tell us the specific code?

if you're throwing out black smoke then it could be a bad o2. But if an o2 was really bad then I don't think it would throw a lean code.

 

Same problem here bud. I need help. 163wtq and 147whp. lean on bank 1. sometimes shoots out black smoke. misfired a couple times.

 

doesnt black smoke mean rich? then how are you running lean?

 

MAF sensor dirty maybe. Check for vacuum leaks.

 

i think i have a leak along with a couple other things

 

Basically on a cold startup the RPM will dip then rev back up. dip to ~500rpm then jump to ~2500. It will just sit and repeat that process until you give it a little gas (aprox 4000rpm) then let it come down slowly it will idle at 800/900rpm.

I pulled the plugs on it just to see if any of them were bad but they checked out ok. But all of them seemed to look like there was too rich of a air/fuel mix. Pretty dark looking. Now.. which comes back to how can my car be running lean? lol

Exhaust wise it sounds fairly weird for "stock". It will crack and pop almost like its not cat'd and as I said before.. will blow smoke from time to time.. Though I can never see it when i'm driving.

Took a video of the car couple days back. Few of my friends wanted to hear the s/c and i just threw the exhaust part on too. Advance the video to ~30 secs in and thats the exhaust.

http://myspacetv.com/index.cfm?fusea...deoid=25024375

You can actually see black smoke shoot out on the last rev.

 

possibly a bad cat?

 

yea, that does sound pretty weird for stock.

 

That could be right.. but its not a complete powerloss at all times. It's kind of random.

But that does have the sound of one.. I remembered it from when the one on my Grand Prix went out. Might take it to a exhaust shop or something then. Have them test it.

j/w. Anybody from IL looking at this? If so could you tell me the warrenty for IL as far as cats? IIRC it's 100,000 miles / 10 years. Just want to make sure though.

 

Hey man I think I know whats up with your motor. When I installed my makeshift shortram into my car, I accidentally rotated the MAF sensor and it ran, but it did exactly what you said, jumped around, kept going till you give it a little gas and settle around 800. Most definitely sounds like a maf problem, its not a vacuum leak because your idle would never level out if the vacuum leak was that serious, Inspect all your stuff though, hope this helps!!!!!!!!

 

So on my way to autozone to grab some MAF cleaner my car was making a really weird noise.. almost like a low key turbo but only when I would get into boost. Stopped for gas... turned the car off... the rpm, mph and radio were "freaking out". guages were jumping and radio was switching thru cd's like no other..

Didnt know what was going on.. tried driving it home.. boosted up to ~19psi according to the boost gauge and barly moved (mph wise). also set off a CEL but it went away so i couldnt scan the code.

Please tell me this is only a PCM problem lol

 

Do you have a car alarm on it or a remote starter.
I have read somewhere that these can bugger things up sometimes electrically.

 

That's a clogged cat...

 

+1...

 

thanks guys!

def was the cat lol

 

How the hell did that happen? Im scared to look inside of mine now.

 

I'm not sure lol Happened on my grand prix too. Looked just like that one. Car only has 14,000 miles.. And instead of just getting a new cat as you can kind of see I just decided to buy the ZZP stage 4 kit.. lol

 

i might need to replace mine, thats probably exactly what it is