Poor Fuel Economy

Fuel economy is noticeably lower than expected. Customer should drive vehicle and note miles per gallon decrease.

POSSIBLE CAUSE ACTION
EGR malfunction
flange gasket leaking,
solenoid malfunction 1. Check EGR system.
If OK, proceed to step 2
2. Check EGR electronic controls.



Initial timing incorrect Check Ignition Timing.



Incorrect Spark Advance Check Spark Controls (SC).



Air damper door binding,
air cleaner temperature
control malfunction Check the inlet air temperature system



Restricted exhaust Check Catalytic Converter.