Poor Fuel Economy

Fuel economy is noticeably lower than expected. Customer detects a significant reduction in fuel mileage.

POSSIBLE CAUSE ACTION


EGR malfunction, Check EGR system
Flange gasket leaking, Exhaust Gas Recirculation
solenoid and thermo valves
malfunctioning



Ignition timing Refer to COMPUTERS AND CONTROL SYSTEMS. Computers and Control Systems



Spark timing Check Spark Controls. Refer to COMPUTERS AND CONTROL SYSTEMS. Computers and Control Systems



Air management valves Check Air Injection system. Air Injection




Restricted exhaust Check Catalytic Converter. Catalytic Converter