Intake Gaskets Help

[GTPWarrior88]

Hey, sorry about the username..I heard somebody else on the board has a similar one..I just used it because it was the same as the one I had on AOL Instant Messenger. But anyways, I do not know what is happening with my 1995 Pontiac Grand Prix GTP 3.4 DOHC. My friend used a scanner and it came up with the Oxygen Sensor. It said Bank 1 Sensor 1, and I brought it to my mechanic and got it fixed. He didn't get a Bosch, because I read some negative comments about it. It ran good for the day I got it back, but then it started to go back to the rough idling it did previously (In the morning..I would start it up and it would stall right away..then I would start it up again and rev it to get it going). My service engine light comes on if I let the car idle for a while. My friend thinks it the intake gaskets that are causing the rough idle, and many people on the message board agreed too. Where are the intake gaskets and is there any diagrams that are on the internet that show you how to change them? Also, I have been told that I might have an exhaust leak..would that affect the idling too? Thanks for the help!

P.S. I am looking for two 12" Sony Xplod Subwoofers Enclosed, but I can't seem to find them anywhere..anybody know where to get them? Thanks!

[GTPWarrior88]

I forgot to add that when I start up the car after it's been running (after the 1st start of the day..anytime)..my RPMs stick between 1500-2000 for a couple seconds and then drops down to about 900.

[10sec.et]

check for other vacuum leaks before pulling the intake. may also have a bad "idle air control motor".try cleaning throttle body and spray carb cleaner into iac port in front of throttle blade.dont spray too much or you can hydro-lock the motor.

[GTPWarrior88]

I have already done the following to my car:
1. Took out and cleaned the IAC.
2. New plugs and wires
3. New Plenum gasket
4. New intake manifold gasket
5. New Idle Air Temp Sensor
6. New Oxygen Sensor

[10sec.et]

try listening to the injectors,if possible,with a stethescope. if there is one that sounds different try tapping on it with a long punch(dont use a hammer) and see if anything changes.i will check "iatn" on monday for common failures.

[GTPWarrior88]

Thanks for the help. I've been talking to many people and trying to get advice from them too.

[10sec.et]

check for a stuck open egr valve. if you have a scantool look at actual opening vs desired opening.at idle they should both be 0. if no scantool,then you will have to remove the egr valve and block off the intake port under the valve(a thin piece of cardboard works fine). start the engine and see if your idle problem is gone.the exhaust side will be loud but thats ok,this is only a test.

[GTPWarrior88]

Thanks again for the info. Could a stuck EGR or a bad one causing stalling idle - the idle sits at a particular rpms for a few seconds until returning to normal? (ex. 1500 for 3 secs then to 900).

[GTPWarrior88]

I don't know if I mentioned this previously or if this helps, but when I scanned it the code came up with P131..which was the Oxygen Sensor. I changed it, and I didn't get a Bosch. It said Bank 1 Sensor 1. I reset the code but it's still coming back on. I checked for loose/bad coil wires but they're all good too.

[10sec.et]

i will have to look up onfo on the p131. as far as the other question, an egr valve stuck open causes an internal vacuum leak. the ecm tries to compensate for this(or any vacuum leak) when it sees a lean o2 reading. this can cause lots of idle problems. egr may not be the problem but i would definitely check it to be sure. it would also be good if you had fuel trim data. from this you can tell if the engine is lean or not. maf sensors can cause some idle issues. you can unplug the maf and start the car.the ecm has a default setting for the maf and will run without it(temporarily). if problems go away,suspect bad maf sensor.it WILL set a code when you do this but can be easily cleared

[GTPWarrior88]

Hey..I checked the egr valve and the mass airflow sensor and they are both cleaned. I have also noticed that it sounds like a misfire in the exhaust. Thanks!

[10sec.et]

misfire sound in the exhaust ? maybe the next step is to do a compression test. could have burned valves or jumped timing. i dont know what the specs are but you need reliable information for this. preferrably a gm service manual.