Thread: 2001 Grand Prix Engine Problems HELP!!!

Hello everyone. I just joined this forum and really hope you guys can help me, I'm running our of ideas. I have a 2001 Pontiac Grand Prix with the 3.8l V-6. This is the problem, any time the engine passes 3500 rpm it sputters and there is a huge loss of power the more you press the accelerator the lower the rpm's get. It idles at 1000 rpm. I first assumed it was running lean due to the well known intake manifold gasket problem, replaced the gasket and manifold and its still having the same problem. I replaced the fuel filter thinking it was starving itself of fuel. I replaced the MAF. I cleaned the fuel injectors. I'm out of ideas other than maybe the oxygen sensors? There are no check engine lights illuminated.The Car has 120k miles but we've only had it for the last 10k so I dont have a complete maintenance record. Any help would be greatly appreciated

Is there any easy way to check to ensure the cat is clogged? Just disconnect it from exhaust manifold? Or Am I better off using a backflow gauge?

Would the cat being clogged cause it to surge and sputter a little also around 1200-1900? Its only in low throttle situations it wants to loose power, and jump around a little bit. fluxuates about 100 RPM then goes on running fine.

Great power and everything. I do have a cat code too though....is this most likely my problem?

i've got a re-occuring EGR and cat code.. we've taken the egr out, and it looks okay, and put it back and both codes come back. hmm.

Alright, Ill try that next, I just thought you smelled rotten eggs when your cat was clogged. Thanks! I'll keep you posted

Sorry for the long delay in getting back to you I've been pretty busy. I completely removed the cat and am currently running straight headers. The car is doing the exact same thing. Once it gets to higher RPM's it starts to sputter and there is severe power loss, and I almost want to say engine knock? I'm really pretty clueless as to what to try next.

Try putting in new spark plugs. wires wouldnt hurt.