So i just finished installing the racing beat cat replacement pipe and presilencer on my 87 NA. Upon starting it for the first time it idled very rough with the RPMs bouncing from 750 to 1500. Also when i tried to rev the car it wouldnt go above 2k. Then when i tried to put it into gear and hit the gas the car bucked and made a popping noise.

A few hours later i tried to start the car and everything went fine. It idled smoothly at 750 when warmed up. I took at out for a spin and it drove fine..for about 5 minutes. Then the RPMs started jumping up and down like before and whenever i hit the gas the car would shake and make a loud bang. So i had to limp/coast back home.

so anyone have any ideas whats wrong with my car?

 

You probably got rid of the split air pipe, since there would probably be no provision on the pipe for it. Did you plug up the hose it attached to at the back of the intake manifold? Also, how are you feeding the 6PI system (your auxiliary port actuators)?

 

I followed the directions from racing beat. The split air pipe is still hooked up to the presilencer. I removed the air pump and and blocked off the ACV with a plate.