While under my recently aquired 93XJ changing the oil filter, I noticed a fair sized hole (about 1.5 - 2 inches diameter) in the exhaust pipe between the manifold and before the cat.. which is probably why my engine has been sounding so good!. It seems to have been drilled intentionally.. its perfectly symetrical and a stainless steel washer has been welded around the edge of the hole as if to stop corrosion and keep the hole a constant size - my question is.. will this have any negative effect on how the engine performs.. will it mess with mpg's, horsepower, or cause any damage through back pressure?.. it sounds awesome!, so Im very tempted to just leave it as is - curious about your opinions. Thanx guys.

 

ummmm......ya thats where the oxygen sensor goes, not supposed to be an open hole. take to your local muffler shop and have a new bung welded on and replace the sensor, get a flowmaster if you want it to sound good.

 

Thanx Tanner - will get it looked at.