1991 loses power

[watermoon]

I have a 1991 Corvette. It consistantly runs well for the first 10-15 minutes. Then it requires more pedal to maintain speed. From a dead stop it hesitates severely. Fuel pressure is fine. Ran scan tool w/ no codes or abnormalities.Replaced fuel; pump and filter, plugs and cap and rotor and new accel injectors.
Does anyone think it could be a coil or distributor module? The problem has been going on for about 3500 miles. I would think a electronic module would have completely stopped working at this time. WHat about clogged cat? Would that cause the problem when cold or not?
Need help. This has stumped a number of mechanics. Any help is appreciated.

[Glennm27]

One Mechanic it will NOT stump, is Steve Spencer at Bryner Chevrolet.

[92RAGTOP]

I had a 90 and the pre cats burnt up crumbled because the egr valve hung up and diverted unburnt gasses to them. the debris filled up the main cat. At low speed below 50mph the car ran fine however when you got on it it bogged down. I removed both pre cats and installed a performance cat (magna flow). The car ran great after that and stayed much cooler also. I went through the same thing I had mechanics scratching their heads replaced wires, plugs, distributer guts with accel parts. Fuel filter even had the fuel system flushed.:confused:

[Rick and Arleen Ball]

Clogged cats could cause your Vette to loose power, but also will cause it to run hot. Hows the temps?
Also could be the Opti Spark.
Good Luck finding the problem.
Rick