Help with the speed!

[Cripton805]

If you enter the highway and get the car up to 70mph or what not by the time you stopped your vehicle, you should be able to look at your catalytic converter and it'd most likely be red from the heat if its clogged. Have someone rev your car while you are behind the exhaust to see if you have much exhaust gas coming out at the tail pipe tip.

Otherwise, the other stuff you state sounds like its a misfire/distributor or like guiltyxxspark said... could be your timing belt jumped a tooth and is robbing you of your power.

When you have a misfire, you hardly feel the exhaust coming out of the tail pipe as well.
Most exhaust shops also have mechanics. I'd just have them check it all out there.

 

[DopenessFool]

Also wouldn't a misfire cause a 'different ' sound at the exhaust?