My cousins crx is having major problems. WHen he takes off in the car if feels like the header/exhaust pipe is slamming into the bottom of the engine. Also, when the car is sitting idle, it like "revs up", its hard to explain it sounds like hes just tapping the gas, the stopping, tapping the gas, like every 1-2 seconds. You guys know whats up with this thing? We think the reason the exhaust is hitting is because of a broken motor mount, because the woule frigin engine moves wen the gas is pressed

 

Broken mount or loss of compression in a cylinder. As for the idling problem. Probably the "throttle position sensor".