Timing Chain problem

Would a bad timing chain cause ur exhuast to sound different?

Probably not. If it were worn enough to cause a different exhuast sound, chances are you would have long ago noticed a huge change in your engine's performance. Usually they are either working or broken, but it depends... what is the car and engine?

Why do you ask? What are your symptoms?

I have noticed a big decrease in engine performance and I know that it is the timing chain that is messed up. Like if I give it more than half the gas pedal it will just fall on its face and not accelerate... its a 1991 Lumina 3.1 mpfi

Then I say (if you're sure its the chain) get it out of there ASAP and replace it. When they go, they go big, taking out valves, pistons, and sometimes rods.

Usually timing chains in those types of pushrod applications go before huge performance differences are noticed, so it may be something else. Fuel pump, injectors, fuel filter, ignition timing, vacuum lines. Assuming you haven't checked those, they might be a good place to start.

falling on its face is a common discription of exhaust problem, the chain may have jumped, or the other common problem is a clogged cat.

can you get it to highway speeds? how fast does the oil go bad? any rattling noises from the engine?(more at cold start-up) ever replaced the cat before? poor gas mileage for the last few weeks/months? do you have emission testing in your state?

Yes I can get it up to as far as the speedometer goes it just takes a long time because the engine performance has decreased greatly and the exhaust sounsd 10x different than before and i have a flowmaster muffler on there. I finally went out and bought a timing chain now ill get it on and see if that fixes the problem.