Spark Knock/Detonation

Check cooling system.
Check fuel pressure.
Check EVAP control system.
Check spark plugs.
Check for high resistance in spark plug wires.
Check for adequate spark with a spark tester.
Check ignition and valve timing.
Check for clogged fuel filter.
Check for vacuum leaks.
Check for excessive combustion chamber deposits.
Check for faulty Throttle Position (TP) sensor.
Check for faulty Engine Coolant Temperature (ECT) sensor.
Check for engine overheating.
Check for faulty MAP sensor.
Check for malfunctioning electronic fuel injection system.
Check for malfunctioning EGR valve.