88 dodge dakota exhaust blowing up?

I have an 1988 dodge dakota 6cyl 3.9l. Recently I had to replace the fuel pump and that area of parts. As well as I just finished the tune up on it. Last month after I had the fuel pump replaced, I was driving it to school aprox. 30 miles away to the Career Center. When I was leaving the highway, I heard a loud pop and then the truck was really loud(blown exhaust.) (The origional muffler blew 21 years old)So I had the exhaust replaced and then it seemed to be fine. But the next week, the truck stalled out on me, so I had a couple more parts replaced(cant quite remember) as well as I had the computer cleaned. And then just recently I was driving down the road and I heard a loud pop again. I returned home and I looked underneath at the exhaust, and the muffler looked warped. So I blew up another exhaust which is under warranty.



I know the engine is backfiring, the plugs are set up right as well as the wires. Could it be the Ignition timing is off? Or what other possibilites could it be?



I have a Haynes repair manual for it. That suggests that it could be ignition timing.88 dodge dakota exhaust blowing up?
I would check the two little wires coming off the pick up it sounds like one maybe coming apart and is shutting the truck off and back on. This will cause it to backfire and blow the muffler. Intermittent connection in the distributor.88 dodge dakota exhaust blowing up?
the reason why your muffler is exploding is because your getting excess fuel it the exhaust system,then it is ignited.it could and probably is a timing issue.so recheck the timing to make sure its right.88 dodge dakota exhaust blowing up?
if the muffler was that old so eas your catalytic converter change that to as far as it missing that is your ignition.
timing issue excess fuel in exhaust then fuel ignited in muffler maybe fuelpressure regulator if its injected