everytime i let off acceleration my car starts to jerk and boggle i hear a poppiong noise from my exhaust at idle i know it could be misfiring but im not misfiring car is smooth while accelerating could this be bad timing or bad tranny ? and when im changing gears it feels harder to get into the next gear and my clutch pedal feels very loose and spungy i feel as if my clutch is about to go soon ? any input does this sound right thanks for all your help guys