So heres the deal, I just bought a 1991 RS with a 305 TBI 144,000 miles. I bought the car with a click, thinking it was a bad cat replaced it with a universal cat. the clicking continued and turned out to be a bad (severly cracked) flex plate. I replaced it with the correct replacement, It ran fine for a week then it would lose power and jump between 1500 to 100 rpm while driving down the highway, then died. I replaced the fuel pump, fuel filter, k&N air filter, distributor cap and rotor, spark plug wires, spark plugs, and did a throttle body rebuild. But it still dies out when I push the gas past 1/4 throttle in gear, and runs perfect in nuetral ( I can rev it up and down for hours and has no issues). also when I hit bumps that are decent size the check engine light turns on for a split second. sorry about the long list but I just dont have any other ideas and want all the details out.

 

Bump, I also show no codes when I plug the scanner in or the paper clip. any ideas would help, I just dont know where else to check.

 

here is a video if anyone wants to see what it is doing... skip to 1:26 to see the main issue