Poor Fuel Economy

Definition: Fuel economy, as measured by an actual road test, is noticeably lower than expected. Also, economy is noticeably lower than it was on this car at one time, as previously shown by an actual road test.

POSSIBLE CAUSE ACTION

Dirty air filter element - Clean or replace air filter element

Fuel Metering - Check air/fuel ratio, (O2 Sensor Voltage)
- Perform CYLINDER BALANCE TEST
- Check vacuum line and return hose
- Check fuel pressure

Air Induction - Check for air cleaner duct and valve door stuck in the "hot air" position, IA4 - Air Cleaner Duct and Valve System Diagnosis
- Check bimetal sensor operation, IA2 - Air Cleaner Temperature (BI-Metal) Sensor Diagnosis
- Check for restricted air filter element, IA3 - Air Cleaner Filter Element Diagnosis

Speedometer inaccurate - Check speedometer calibration.