Additional Checks

Check the vacuum hoses for splits, kinks, proper routing, proper connection, and fuel loading. Refer to the Vehicle Emission Control Information (VECI) label.
Check the Secondary Air Injection (AIR) check valves for proper operation.
Check Torque Converter Clutch (TCC) operation. See appropriate DIAGNOSIS article in TRANSMISSIONS.
Check the exhaust system for possible restriction. Check exhaust system for damaged or collapsed pipes. Check the mufflers for heat distress or possible internal failure. Check for possible plugged 3-way catalytic converter. See RESTRICTED EXHAUST .