One of the main causes of feeling a vibration in the gas pedal is engine vibration. The vibration from the engine causes the accelerator cable or linkage to vibrate and the vibration can be felt in the gas pedal. Check with a mechanic to be sure.
Will a 2.2 engine out of a 1996 Toyota Camry fit in a 1997 Toyota Camry? Yes it will fit you just have to change from distributor to coil packs it will fit because i have a 96 Toyota camry with a 2.2L engine from a 99 model.