My muffler exploded! Has anyone else had this happen? What was the cause?

What is the make, model and year?
It could be: bad diverter valve, bad spark plug wires, shorted coil pack, etc.

Don’t worry. If it was an IED it would be over before you ever heard it.

It’s a 1989 Mitsubishi Minicab. Not usually available in the US. 500cc engine, manual trans. carbureted, 3 cyl.

It is possible that it is because of a backfire.

Too rich a mixture. Could be a sticky fuel float, bad decel throttle cracker (if you have one). Has your fuel economy gotten worse recently? Did you remove the catalytic converter.?

what makes a backfire? how does it happen?

I don’t really know but something similar seems to have happened to other people and this is what Ray and Tom, the Car Talk guys have to say about it.

If your spark is interrupted or if the spark plugs aren’t creating enough spark to start the car, unburned gasoline can collect in the exhaust system. And then, when the car finally does start, that unburned gas can ignite.

The link is kind of funny if nothing else.

It would normally just cause a backfire I think, as mentioned, but I suppose if enough unburned gasoline collected it could blow up your muffler. I don’t know.

Did someone play a nasty trick on you and stick a potato up your tailpipe?

I got a new muffler put on this morning and am keeping the old one (practically new, no rust) to hang on the mancave wall.