the car has ~60k miles; the car is shaking when idling in drive or neutral(doesnt shake while in park); especially when you let off the brakes in D. my cousin(~1995 Chrysler xx) also had this problem; her's was fixed by replacing the spark plugs. i just changed the spark plugs today to see if that would fix it(from stock Champions to Bosch Platinums). problem is still there. what can i do to fix this? im thinking there might be a vacuum leak, clean the IACV, or resetting the ECU?(btw, the stock plugs had burn marks on the plugs) any help appreciated, thanks.