Problems!! HELP!

[3400Camaro]

okay, this is an ongoinging problem for me, and i'm getting fed up with my car! my 3.4 is getting about miles a gallon. it's slower than dirt, i'm doing good if i can get this thing up to 105mph and hold it there. my plugs are new, yet are all carboned up. if i let it sit an idle in a certain spot for long it will leave a big blag spot under the exhaust tip. i've had it to the mechanic, he says all sensors are fine and the computer says all is normal. this isn't normal. someone please help!!!

[MississippiMaro]

This is a shot in the dark, but have you checked your EGR lately. It has been known to cause many a camaro owner grief in all areas of the engine. PLus i've heard it causes hatch rattle and leaky t-tops, but i don't know if I buy into that, LOL. If you have a chiltons, it should give you some diagnoses for excessive carbon buildup. Hope this helps

[phoenix64]

Have you checked your catalitic converter. My old jeep was acting really powerless, and it was a pluged cat.

[speeder]

I'd say check your oil level, maybe you've got too much oil leaking past your rings or another maybe bad valve guides. If your car smokes on start up-worn valve guides, if it smokes all the times-bad rings. If you get too much oil on your plugs(carboned up) you could have bad over all driving problems. If your car dosen't smoke I couldn't tell you. Smell the fluid leaking out your tail pipes, they may give you an indication of what is leaking.