Well my exhaust is ok....nothing special since it a LO3. I have stock manifolds, stock y-pipe, 3" intermediate pipe, and 2.5" y-pipe in place of the muffler. (i.e. no muffler) It's nice and loud and all but when I hit higher rpms and just let the rpms drop by themselves it back fires like crazy. it sounds nice and throaty then POP!! It's really annoying and I'd like to know what is causing it. I got under the car the other day and where the guys at the shop welded the y-pipe there are a couple of small holes. Would this cause it, or just the lack of back pressure? I just want to know what to look for so I can fix it. Any suggestions would be nice

 

I don't know if it's true, but I think cool air mixing with hot exhaust gases can cause detonation in the exhaust...

 

so the possibility of cold air being sucked into the exhaust through the holes might be causing the problem? Well I will just weld it back and see if it fixes it, if not then I might have to resort to putting a muffler back on

 

Before you go through all that hassle, check your Diverter Valve. and hoses.

 

i have the same problem you either have holes in your exhaust sucking in cold air or youhave low back pressure and are sucking the cold air back through the tailpipe you either have to put a muffler on it , fix the holes, but something on it to create more back pressure, or deal with it

 

excuse my ignoracne, but what is a diverter valve?