Visual and 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 and physical inspection:
^ Inspect all of the vacuum hoses for the following conditions:
- Correct routing
- Pinches
- Cuts
- Disconnects
^ Inspect the 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 items:
- Proper connections
- Burned or chafed spots
- Pinched wires
- Contact with sharp edges
- Contact with hot exhaust manifolds

This visual and physical inspection is very important. Perform the inspection carefully and thoroughly.