Backfire

1. Defective ECU.
2. Open or shorted fuel injector circuit.
3. Stuck fuel injector.
4. Defective fuel pump main relay.
5. Poor fuel pump ground.
6. Open or shorted manifold air pressure sensor circuit.
7. Broken or disconnected manifold air pressure sensor hose.
8. Defective manifold air pressure sensor.
9. Open or shorted coolant temperature sensor circuit.
10. Defective coolant temperature sensor.
11. Open or shorted throttle angle sensor circuit.
12. Defective throttle angle sensor.
13. Defective EGR control system.