Section 6 (Engine Controls - Tests W/O Codes): Symptoms: Backfire

WARNING: This page is about a different car, the 1996 Acura SLX. However, it is still accessible from the selected car via links, so may be relevant.

Check ignition timing.
Check ignition coil output.
Check for faulty spark plugs.
Check EGR system.
Check for crossfire between spark plugs.
Check for sticking or leaking valves.
Check for improper or worn camshaft.
Check engine compression.
Check fuel pressure.
Check for correct valve timing.
Check for cracks in exhaust and intake manifold.