Thanks for your reply. I pulled the air cleaner and intake hose. I found a ball wad of plastic (similar to electrical tape) in below the air filter. I ran it again and had slightly better rpms. As you said in your post, it didn't stop right at 3500. It accelerated slowly past 3500 up to 4000 rpms. At 20 mph in neutral, I could run it to 6000 rpms a couple of times. At 40 mph it would only go to 3500 - 4000. It does sound like its starving for air. I think I hear a slight miss or pop occasionally, but I think the timing is okay. And it idles fine. Also, the exhaust looks straight, although the muffler does look like its rusting and needs to be replaced.Thanks.

 

if you can, drop the cat, and look at the honeycomb inside. I have a couple of car that have came through the dealer with the same probs as you and the honeycomb was broken blocking the exit. Have you ever changed the timing belt??? I would take off the vavle cover and put the crank at TDC and make sure the cam lines up also.

 

Was gonna suggest what the guy above said, check the cat, could be super clogged. Unblot it and start the car to see fi the problem gets fixed.

 

Thanks HatchVX and menappi. The more I hear and read it sounds like it could be a bad cat. Depending on how hard it is to remove, I may need to send it to the shop. I'm thinking they could pull a vacuum on it to see if the cat is bad. And I'm wondering if it could be the 02 sensor located nearby.

 

Jack the car up and un bolt the three bolts that hold the cat to the downpipe and fire that baby up.

 

I had the same issue. Granted it was with an inline-6 in a 1977 Camaro, but still. It would get up to 3000-3500 RPM then bog down. Turned out my cat had collapsed.

 

I loosened the 3 bolts at the front of the cat like menappi said and the rpm's shot right up. Thanks to everyone who said to check the cat. It looks like were in business again!

 

instead og getting a new cat for about 120 bux, you can just get a high flow cat from e-bay for like 25 bux. i don't usually recomend stuff from e-bay, but i got one, and it seems to be holding up nicely. well, it's more like a test pipe, but it still works.

 

That's all good and fine until you get your emissions done. Not to mention it's not very good for the air.