- Visual/Physical Underhood Inspection

VISUAL AND PHYSICAL UNDERHOOD INSPECTION
A careful visual and physical underhood inspection must be performed as part of any diagnostic procedure or in finding the cause of an emissions test failure. This can often lead to fixing a malfunction without further steps. Inspect all vacuum hoses for correct routing, pinches, cuts or disconnects.

Be sure to inspect hoses that are difficult to see beneath the air cleaner, compressor, generator, etc. Inspect all the wires in the engine compartment for proper connections, burned or chafed spots, pinched wires or contact with sharp edges or hot exhaust manifolds. This visual/physical inspection is very important. It must be done carefully and thoroughly.