Backfire

[The_man78]

So I had an engine backfire. its created less horsepower, poor gas mileage, and my exhaust sounds funny. I have a deep throaty racing exhaust and it doesn't sound like it used to. I thought that maybe my cat converter was clogged. Turns out that was good. I am unsure of what else it could be. Anyone know?

 

[Ganyon]

Maybe you should do a compression test. You probably have a dead cylinder or possibly blew the headgasket.

 

[Muckman]

Backfires aren't typical of a stock engine and indicates something is afoul. A backfire in itself can be dangerous. I've melted intake temp sensors and bent exhaust valves during backfires; Ive also blown exhaust slip joints apart, fun stuff while hitting 30psi boost cuts.

Ganyon is right on with the compression test. You probably have a burnt valve or bent valve. Could be missing the tip of the spark plug too.

 

[Nick_C78]

I was actually going to suggest bent exhaust valves. Especially if his harmonics are off. Have you pulled the plugs to see how they look at least?

I third the compression test.

 

[The_man78]

I haven't checked the plugs because my friend is doing some work for me. I will check them soon. They were just replaced not long ago. Wires too. I'll run the test and let everyone know. Oh the exhaust does smell funnier than usual as well.