Originally Posted by Stang Seller

I dont think your problem stems from running Flowmasters, thats the most ridiculous thing I have ever heard (no offense). I've had Flowmasters on many of my cars and I've only had the backfiring issue on my best friends '95 when we switched to an off road h pipe and only on a hard downshift. That was fixed when I installed a pair of new 02 Sensors. I've even had a speed density vert that ran great with a K+N, B-cam, shorty headers, off road H pipe and Flowmasters and the car never backfired.
By backfire are you talking about a loud POP or a series of pop-pop-pop sounds?
SS