1994 Pontiac Firebird • V8 2WD Automatic • 122,000 miles

It sounds normal when it's cold and I power brake it, it will smoke the tires. After it warms up, it won't It doesn't smoke and doesn't knock so I unless it's a computer issue, I don't know whats wrong with it. I bought it not running and was told it needed optispark. I replaced optispark and engine runs but no power. Transmission shifts good with no problems, when I am driving I push the gas all the way and it accelerates like half throttle
January 9, 2011.

Have the computer scanned for trouble codes. Make sure the catalytic converter isn't plugged. Check for any vacuum leaks as well as check the EGR for plugging.