firstinlastout86

iTrader: (4)

So we just got my gf her first camaro its a 2000 z28 a4 its got 164k miles, we picked it up from a member on here last week for 4,250. Seller stated that it had a pretty bad exhaust leak. We met up and the car was running great no knocks,we had it idling for probably 30 min with no overheating problems, trannys great, rear is quiet..etc aside from the extremely bad exhaust leak coming from the drivers side exhaust manifold everything is straight the leak was coming from where the manifold bolts up to the cat...out of the three bolts only one was remaining i was told this occurred while gutting the cats either overtightened or while loosening..I'm not sure either way we drove the car home and it ran fine from what i remember. Got it up in the air and we replaced the manifold with one from a buddys t/a. This is where the problem starts. We start her up and while the exhaust leak is fixed it seems to be missing or surging giving the bay a once over i noticed we forgot to plug in the MAF and IAT sensors so i had her shut off the car and i plugged them in and it still surged/missed with a low idle around 400-500 and when driving while slowly giving it gas it kind of jumps/stutters forward until into a higher rpm..so after checking for more unplugged sensors i found everything was in its place so after researching on here i decided to do a couple things..first i re-checked all the plug wires and sensors..with no change i reset the PCM..nothing..then i read the surging and missing could be from a vacuum leak so i looked around the intake manifold for loose or unplugged vacuum lines with nothing obvious showing i sprayed some break cleaner around with no spike/change in idle. So back to ls1tech...this time i read the o2 sensors being bad could cause symptoms like this and i figured possibly from running with the bad exhaust manifold for 300+ miles could have F-ed it up..so after the car sitting for 48 hrs i replaced the D.s front o2 sensor..moment of truth.. we started her up and at first it seemed to have fixed the problem idled fine no surging no missing..everything seemed fine then about 20 min later it started with the same **** it slowly got more noticeable as we let the car run..so here i am...i have no idea what to do now I'm sorry this is so long but i swear i put off starting a thread and did as much searching as i possibly could....any help....

conan

iTrader: (5)

Did the check engine light come on after you replaced the O2 sensor? Did you replace both of the O2 sensors? Might want to throw in another O2 if you only did one. You could also try to clean the MAF.

firstinlastout86

iTrader: (4)

Here some more info....

--Seller tells me he had the EGR and AIR tuned out and also had the shift pressure changed by a buddy with HP tuners and found out this was one while it had the exhaust leak...

--Mods are a LID and LM1 !EGR !AIR

--Could him gutting the cats cause these issues?

-- I will be bringing the car to MASPORT to have dan give the tune a once over

firstinlastout86

iTrader: (4)

Thats the thing never threw a CEL....still hasn't
I replaced the front DS o2 only
and I knew I forgot somthing....we did clean the MAF
tomorrow i will unplug the PCM and clean the connectors she just read that can cause this ..

thanks for the fast response!!

conan

iTrader: (5)

I would try replacing the other O2 as well. Removing the egr and air will only set off the ses light it won't make the car run like ****. Also do you know if the rear O2's have been tuned out after he gutted the cats?

firstinlastout86

iTrader: (4)

ok tomorrow ill get the rear driver side o2 what about the pass side ones?

he did not have the rears tuned out..ill double check tho

firstinlastout86

iTrader: (4)

anyone else?

00SS6spd

iTrader: (3)

I think he meant to change the PASSENGER side front O2 sensor. The two front O2 sensors are what determine how the car runs, the rear two are strictly for emissions purposes. Try replacing the passenger O2. It could also be the TPS, or the IAC going bad if you already cleaned/checked the MAF. I'd definitely check them, those two sensors can cause all sorts of hell if they go bad, get dirty, etc...

jam01

when checking for vacume leaks, you should have used carb cleaner or something similar. you should spray it in small areas and listen for your idle to rise.

firstinlastout86

iTrader: (4)

ok cool so tomorrow ill be going to putting in a PS front o2 and ill recheck for vacuum leaks with carb cleaner although i figured the break cleaner would have had the same effect both being very combustable..no?

anyone have any other ideas?

00SS6spd

iTrader: (3)

TPS and IAC

Zaxz28

That same thing happened to me and it turned out to be a loose spark plug wire just barely hanging on, make sure they are all pushed in.

firstinlastout86

iTrader: (4)

UPDATE:Today I repalced the pass. side o2 sensor,RE checked all sparkplug wires, RE checked for vacuum leaks, re-cleaned the MAF,cleaned the PCM connectors, cleaned the TPS,IAC and IAT sensors with no ******* changes....still idles like ****..missing and surging...So i went out and bought a new TPS and IAT sensors took em home hooked em up reset the TPS and fired her up.....same ****?!!!?!???!??? I guess ill have to save and spend the 125.00 they want for the IAC sensor and we'll see what happens.....for now tomorrow ill take out all the spark plugs and see if they were gapped properly could this be the MAF?

firstinlastout86

iTrader: (4)

any other ideas

00SS6spd

iTrader: (3)

If the new IAC doesn't help, see if you can find someone with a stock MAF that's willing to let you swap for a minute just for the sake of seeing if it fixes the problem. It's possible you may have damaged the contacts on your MAF while cleaning it.

LS1babe

iTrader: (2)

Hi everyone- I am the above stated girlfriend whose Z just won't idle right... anyhoo...

I cleaned the MAF the other day and (please bare with me and correct my vocabulary if incorrect) one of the three hotwires in the MAF wouldn't really clean up all the way. Everything came clean except one. It's still black. By any chance could this mean that the MAF is bad and causing the idle surging?

Also, I checked again for a couple potential vaccuum leaks with carb cleaner and got nothin

We also removed one of the spark plugs which was gapped incorrectly. Guessing the others are probably incorrect as well. Could this be the problem? Kinda wanted to buy new spark plugs anyway... LOL say yes so I have an excuse to buy them

conan

iTrader: (5)

X2 do you know any one that would let you try their MAF? Those wires are delicate.

firstinlastout86

iTrader: (4)

ya my buddy tripplewhite96 if he would ever stop working and return my calls ....lol im going to try to switch out with his IAC motor too....

conan

iTrader: (5)

Thats what I would try next.

firstinlastout86

iTrader: (4)

thats what we will do thanks for all your help!!!