Visual/Physical Underhood Inspection

Perform a careful visual and physical underhood inspection when performing any diagnostic procedure or diagnosing the cause of an emission test failure. This can often lead to repairing a problem without further steps. Use the following guidelines when performing a visual/physical inspection:
^ Inspect all of the vacuum hoses for correct routing, pinches, cuts, or disconnects.
^ Inspect any hoses that are difficult to see beneath the air cleaner, the A/C compressor, the generator, etc.
^ Inspect all of the wires in the engine compartment for the following conditions:
- Burned or chafed spots
- Pinched wires
- Contact with sharp edges
- Contact with hot exhaust manifolds

This visual/physical inspection is very important and must be done carefully and thoroughly.