good evening ladies and gentlemen,, 2hrs ago - went to the gym , on return i started my car up and low and behold a disgusting sound appeared to be coming from my engine bay and underneath and possibly exhaust,, i had a look under the car no visible signs of damage, for information required i have an 03 stivo with ces exhaust and cai and other bits.. im not sure what may have caused this problem.. im currently running small doses of upper cylinder head cleaner aswell but im sure that this is not the cause.. could anyone offer suggestions.. cheers GREG