Hi lol well it has to go somewhere. The system you have is a pre obd system there is a plug under the dash under the coloumn or even over in the middle it is a black plastic plug you put this tool they gave you in the last two terminals this will cause the check eng light to flash. It will flash a code as in two quick flashes and pause 3 quick flashes would be code 23 this will tell you what is causing the light to come on.
Asfar as can your exhaust leaking cause a check eng light possibly the oxygen sensor has sensed a wrong reading from the exhaust. But most likely these two problems will not be related. Good luck. Billymac
Thursday, February 16th, 2012 AT 10:56 PM