Preliminary Checks
Be sure fuel is actually reaching the injector. Make sure no air is entering the intake or exhaust system above the catalytic converter. Before assuming an engine control system malfunction, inspect the following systems to ensure components are in good condition and are operating properly.
- All support systems and wiring.
- Battery connections and specific gravity.
- Electrical and vacuum connections on components and sensors.
- Emission control devices.
- Ignition system.
- Vacuum hoses.
CAUTION:
Never connect or disconnect a component without turning the ignition switch off. Never apply more than 12 volts or AC voltage to system terminals. Disconnect battery cables before charging it. Remove ECU if temperatures are expected to exceed 176°F (80°C), such as in a paint shop bake oven.