Backfiring car

I own a 1988 Camaro Iroc-Z with a 5.7 350 TPI motor.
I was driving the car onto I-95 at a speed of 65 when I heard a loud boom under my car, and pulled over to see what had happened. I couldn’t see what happened, so I drove the car slowly to a friends garage to find the exhaust pipe from the converter back to the muffler had split and blew apart.
I took my car to another shop to repair the pipe, but when I left the shop after the repair, I accellerated to about 40 mile per hour, I get another loud backfire and loss of power. The pipe is still intact, thank goodness, but I cannot figure out what is causing the backfire.
My friend from the first garage says it is a failing fuel pump. I never heard of such a thing to be honest.
I am at a loss and I have to correct the issue soon, as this is my only car to drive.

Please Help me ?

I don’t buy the fuel pump either, I would look for a leaking injector. Something is dumping raw fuel into the exhaust and when it builds up enough, it ignites. You should be noticing a misfire or roughness in the motor, especially at start up.

Another cause would be a burned exhaust valve, but again, you should notice a rough idle.

A bad fuel pressure regulator could also force excess gas into the engine.

If the engine idles smoothly, then a leaking injector becomes most suspect. I’m not sure, but I think your engines uses a lost spark ignition, you can identify this because it will have four coil packs with two spark plug wires from each one. No distributor. With this engine, you get a spark at every TDC, not just the compression stroke. On the other stroke, the one with the lost spark, both valves are open. The MMF (motomotive force) created at this point helps draw the fuel/air mixture into the cylinder faster, but a leaking injector would put enough fuel into the cylinder to cause it to ignite and backfire.

My memory is very hazy on this but I think the problem could be in the A.I.R. system; meaning the Air Injection Reactor. This car may have a belt driven pump which injects fresh air into the exhaust under certain conditions and backfiring can be due to a problem with the diverter valve or a problem with the ECM control for that valve. Odds are the diverter valve has gone south.

Backfiring is the symptom when a problem occurs in this area so it’s something to consider.

I decided to take a quick look for this valve and OUCH.

That thing is pretty pricy so I wouldn’t replace it on a guess. Do the proper diagnostics first.
If the valve is bad then you might consider digging around on eBay or a local salvage yard for a used one.
I’ve used the eBay seller “thirdgenparts” several times for Camaro parts of this vintage and if they’re still doing business then they should be reasonable on the price and they’re good to deal with.

A failing fuel pump or plugged filter would make it backfire through the carb or intake plenum.

A leaking injector is a possibility but so is an ignition component that is failing off and on. It would allow unburned fuel to build up in the exhaust when off and then ignite it when ir came back on. Does your car seem to pause before it backfires?