When im taking off or put on the gas the car

Make sure you renew your fuel filter every 35000 miles.Also, check the exhaust flow out of your tail pipe. The catalitic converter may be cloged up.It happens.Have someone press down on the gas while you feel the flow out of the tail pipe. Does it feel restricked? I had to have mine on my 2001 replaced at only 44000 miles. I had them put on a "High Flow" type.