I have a 1994 3.8L and recently done a head gasket replacement. My brother and I did the job and got the job put back together. Since the car has been put back together I'm losing pedal response. I can drive about 1/4 to 1/2 of a mile and the car will start to lose pedal response. Seems like when the pedal goes its around 2k rpms and when it kicks back in it hits 1k rpm. The car idles and runs good with the exception of the said problem above. I've changed the tps, dpfe sesor, the egr solenoid and checked the mass air flow. We've hooked an obd2 scanner to it when we first noticed the problem and it read bad tps and now its reading code p0402 which is egr excessive glow detected. Im stumped and any ideas or suggestions would be greatly appreciated . Thanks

 

Check for vacuum leaks at the hose going to the egr valve make sure ya hooked it's hose up to the intake manifold. Second clean the egr valve third replace it