- 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 the vacuum hoses for correct routing, pinches, cuts, or disconnects.

- Inspect the hoses that are difficult to see beneath the air cleaner, A/C compressor, generator, etc.

- Inspect all the wires in the engine compartment for proper connections, burned or chafed spots, pinched wires, contact with sharp edges or contact with hot exhaust manifolds.

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