Ok so here is my problem, I put headers, plugs and wires along with a h-pipe on my 91gt and with no pipes and it drove fine with all power... so here is where the problem starts, I got a guy to weld side pipes on it. I got the car back drove it home and floored it and it had no power. I pulled all the plugs rechecked all plug wires and still nothing. I replaced the tps, aic, act sensor, the ecm, maf, and the fuel filter.Took off the upper and lower intake cleaned them both and still nothing. The car is stock besides the fender mount and others I mentioned. My brother and I are both stumped. Btw its an auto. What stumps me is the only defining thing is the side pipes. Thanks in advance.