Symptoms

- Engine Light ON (or Service Engine Soon Warning Light) - Lack/loss of power - Hard start - Engine hesitation

Possible Causes

- Blocked intake or exhaust system - Mass Air Flow (MAF) sensor faulty - Faulty spark plug 1 - Faulty ignition coils - Ignition coils harness is open or shorted - Ignition coils poor electrical connection - Clogged or faulty fuel injectors - Injectors harness is open or shorted - Injectors poor electrical connection - Improper spark plugs - Insufficient cylinders compression - Incorrect fuel pressure - Intake air leak

When Detected

Random/Multiple Cylinder Misfire Detected

Description

When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the Crankshaft Position (CKP) sensor signal to vary, the Engine Control Module (ECM) can determine that a misfire is occurring.