If your vehicle is showing loud popping or backfiring noises from the exhaust, here are the most likely causes and the parts you'll need to fix each one.
A leak in the exhaust system introduces fresh oxygen, which ignites unburned fuel in the hot exhaust pipes. This is especially common if exhaust clamps or gaskets were recently replaced and not fully tightened.
Worn spark plugs or failing ignition coils cause the engine to misfire, dumping unburned fuel directly into the exhaust where it violently ignites. Incorrectly gapped plugs or crossed wires during a tune-up can also cause this.
Faulty sensors can trick the engine computer into injecting too much fuel. The excess fuel that doesn't burn in the engine ends up igniting in the hot exhaust system.
Installing a high-flow exhaust or muffler delete reduces backpressure and sound deadening, making normal deceleration fuel-pops extremely loud. This is often an expected result of exhaust modifications without an ECU tune.
If the engine's timing is off, the spark plug may fire while the exhaust valve is still open, causing combustion to shoot directly into the exhaust manifold. This often happens if a timing belt was recently installed off by a tooth.
A burnt, bent, or sticking exhaust valve fails to seal the combustion chamber, allowing the explosive force of combustion to leak directly into the exhaust. This is a major internal engine failure.