Car won't go above 20mph

[kn0x47]

Well, I feel like it will accelerate faster regardless, no? Haha!

no. a stock motor is tuned to have a cat and exhaust. going straight pipe will reduce back pressure too much and slow it down. the fact that he had to let the car sit for a while before it corrected itself would imply that too much pressure is being built up on the exhaust side of the motor. Cats are the most common cause of that

 

[DarkSideAccord]

i wanna say that u have a clogged cat... just put your hand near the exhaust tip and have someone rev the motor.. if u can barely feel an exhaust fume coming out, then it's clogged... happened to me before.. it'll progressive get worse until the motor won't turn back on

 

[james'99]

no. a stock motor is tuned to have a cat and exhaust. going straight pipe will reduce back pressure too much and slow it down. the fact that he had to let the car sit for a while before it corrected itself would imply that too much pressure is being built up on the exhaust side of the motor. Cats are the most common cause of that

While I tend to think that way too, I still feel like there would be a little gain. Not too sure. But you can also check the inlet and outlet temps of the cat.