It's a 2002 Trans Am WS6, just bought it 3 months ago. I've replaced the catalytic converter on driver's side, and the entire intake manifold gaskets on the car. It has a "professional products" intake manifold on it. The car also had a vacuum leak that got resolved. I drove the car for a month with no issues, but as of a few days ago, the service engine light came on, then turned off the next day. Yesterday it turned on again and has stayed on. Seems no real driveability issues other than every once in awhile I'll notice it idling low, around 500rpm. The car is an automatic and has no other aftermarket parts on it other than the manifold. I know, strange huh? Let me know what you guys think this is. Thanks!

 

Go hear and diagnose the codes.

http://gearchatter.com

 

P0174 and p0171 are lean codes on bank 1 and 2 you still got a vacuum leak somewhere. Check if you didn't pinch a gasket or if any vacuum hoses got left off. Also check your secondary air system for suck valves or cracked hoses.

P0300 is a missfire detected code this is most likely cause from the vacuum leak you have.

 

I listened to the engine, and sounds like there's a vacuum leak around the MAF. I didn't see any hoses off or anything. Possibly the gasket for it?

 

check for your intake leak also cause missfire

 

Try spraying some engine starter fluid around the area you think has the vacuum leak. If you see a change in the idle of the engine your on the right path. check the boot after the maf to see if it has tear. Any unmetered air will cause a lean condition. check the throttle body gasket and the vacuum sources near the throttle body.

 

It's my intake manifold gasket again!! This time we used the upgraded black gasket and still leaking again. After only 40 days!!!!

 

If the gaskets leak again maybe the issue is the intake manifold. Did you torque the intake to specs? Check if on or more threads on the cylinder head for the intake bolts are stripped.

 

torqued to specs. We re did it again on saturday. The driver side gasket is the bad 1. The passenger side was bad. It looks though as if WATER is getting on the gasket itself. Like rain water. Both sides got this. Port-wise on the gasket, it was the front driver port and rear driver side port. That's the 2 that were tore. we put form a gasket on the gaskets this time, so maybe that will help? I'm not sure it will though. I do have the button type screws with allen head ends on them also. Gaskets I used are professional products fel-pro part # 52610. Supposed to be best gasket for this manifold. We put threadlock on all the bolts to make sure they dont come loose. I have done everything I could with this manifold. i called professional products and they had absolutely no suggestions. Other than saying their "manifold works". Anyways, if this doesn't work, this intake is going off and I will find an ls6 intake for it.