- Preliminary Information

This section is used to find the correct test procedure for a given symptom. The symptoms and actions in this section are Emission related only. Always use the Flow of Diagnosis for proper testing sequence. Verify the correct system application to ensure that the vehicle has the given component(s).

ATTENTION: Before proceeding to the appropriate symptom perform the following inspection: A satisfactory exhaust emissions test includes making sure the vehicle's engine and emission control systems are fully warmed up prior to conducting the test. An engine coolant temperature gauge that reads operating temperature or a warm radiator hose does not necessarily mean that the vehicle is ready to be tested. For example, although the engine coolant temperature gauge may be reading at operating temperature, the catalytic converter may not be fully warmed up, which may cause exhaust emission levels to be artificially high and not representative of whether the vehicle's emission control systems are functioning properly. Therefore, if the vehicle has been turned "OFF" or sitting at idle for several minutes, even though the engine coolant temperature gauge indicates the engine is at operating temperature, the vehicle should be driven on the road for a few minutes just prior to starting the official test to ensure that the engine and emission control systems are fully warmed up. An alternative warm up method that can be used and may be more convenient is running the engine at about 2500 rpm for two or three minutes with the transmission in park or neutral.

VISUALLY CHECK:

1 Vacuum hoses for splits, kinks and proper routing.
2 Ignition wires for cracking, hardness and proper connections at both the distributor and spark plugs.
3 All wiring for proper connections, pinches and cuts.
4 Harnesses for proper routing.