Poor Fuel Economy

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

POSSIBLE CAUSE ACTION


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


Ignition timing Check Ignition Timing in "Adjustment
Procedures"


Spark timing Check Spark Controls in
"Testing Procedures"



Restricted exhaust Check Three Way Catalytic Converter in
"Testing Procedures"