strange problem
strange problem 94 Z28 A4 it has lost all power ,runs hot, has a wierd hiss when accellarating,or trying to accellarate anyway,and the exhaust sound has disappered.The car used to have a moan to it at cruising speed now all you hear is this wierd hiss.It has a flowmaster cat-back which I hate but all of the sudden it sounds quieter than stock at any rpm.It has also lost throttle response.Seems to have a strange smell too.I have checked the vacuum and it seems fine.I have looked for vacuum leaks but have found none.If you have ever ran out of gas with a carberated motor,the way they sound like its sucking in alot of air through the carb,my LT1 sounds like that through the air intake.I havent checked fuel pressure yet but will soon.Makes me think the cat has stopped up but by the vaccum gauge I dont think it is stopped up.The gauge falls back to normal reading pretty fast.IF ANYONE HAS ANY HINTS PLEASE CHIM IN, MY DUMBASS CAN USE THE HELP,THANKS
Originally Posted by HBHRacing
Check for a clogged converter.
Originally Posted by HBHRacing
vacuum isn't a good test for a converter. The only way to know for sure would be a back pressure test. Most exhaust shops can do one for you. The symptoms and the noise fits.
