Hi Guys, My son has a 96 Mustang GT v8 w/Manual Trns. He had a H pipe put on with the dual exhaust. He installed the O2 by-pass kit to turn off the check engine light. The car ran great for a few months with no trouble. All of a sudden the car began to hesitate and feel a miss when going through the gears. It seems to do it under a load. He has changed the plugs, coil paks, wires and gas filter. He also tried disconnecting the sensor in the air hat and it ran even worse. He also tried disconnecting each injector while the car was running and there was a big difference in each cyclinder so it seems they're working. Anybody have any suggestions or had the same trouble? Thanks Alot JT