1st: my muffler is blown
2nd: I can feel good flow coming out of the cat. (not by hand, dust and dirt
sturring up real good when running in the garage)
3rd : Scared to put a new muffler on, with the thoughts of possibly
blowing the new muffler, been down that road before.
4th: Only backfires after being driven for a while, engine is good and warm
usually about 7-10 miles. The harder I drive it the louder the backfire
If I am easy on it, it is more like a "poof". sounds like its right at the
front of the muffler, which is the blown end.
Also, I could make it backfire on command before (I really know my Jeep), but in the last couple of months I have made it my DD. I had so many bad vacuum leaks before, I was only getting 8-9 MPG and now I am getting 15-16 after fixing those.