Additional Checks
- Inspect the vacuum hoses for splits, kinks, proper routing, proper connection, and fuel loading. Refer to the Vehicle Emission Control Information (VECI) label.
- Inspect the intake manifold and the exhaust manifold passages for casting flash. See appropriate article in ENGINES.
- Inspect for proper operation of the Torque Converter Clutch (TCC). See appropriate DIAGNOSIS article in TRANSMISSIONS.
- Inspect the exhaust system for possible leaks and/or restrictions. Inspect the following:
- Inspect the exhaust system for damaged or collapsed pipes.
- Inspect the mufflers for heat distress or possible internal failure.
- Inspect for possible plugged catalytic converters.
- Electromagnetic interference on the reference circuit can cause an engine miss condition. A scan tool can usually detect the EMI by monitoring the engine RPM. A sudden increase in RPM with little change in actual engine RPM change may indicate that EMI is present. If a problem exists, inspect for high voltage components near the ignition control circuits.
- Inspect the Park/Neutral Position (PNP) switch operation. See appropriate DIAGNOSIS article in TRANSMISSIONS.