I just had replaced my my pipe from my cat to the muffler from 2" to 2 1/2" and put a muffler on with a 3" tip.Now im having a rough idle.The only thing ive done was a short ram intake.Theres no vacume leaks,the plugs are good and tomarrow im gonna check if its running rich or lean.Does anyone have any idea why this would happen all of a sudden?