- Visual/Physical Underhood Inspection

Several of the symptom procedures ask for a Careful Visual/Physical Check. This step is extremely important - it can lead to correcting a problem without further checks and can save valuable time. This check includes:

^ The PCM grounds for being clean, tight, and in their proper location

^ Vacuum hoses for splits, kinks, and proper connections, as shown on the Vehicle Emission Control Information label - Check thoroughly for any type of leak or restriction

^ The Mass Air Flow (MAF) sensor installation. The arrows on the plastic portion of the sensor must point toward the engine

^ The air intake ducts for being collapsed or for having damaged areas.

^ Air leaks at throttle body mounting area, Mass Air Flow (MAF) sensor, and the intake manifold sealing surfaces

^ The ignition wires for cracking, hardness, proper routing and carbon tracking

^ The engine harness wiring and terminals for proper connections, pinches or cuts

^ Inspect suspected system/components electrical connectors for water intrusion. Water intrusion causes non-typical failures.