Why has my mileage dropped? Dealership says everything looks good and supposedly checks out, sir filter is clean and the engine runs great.
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2007 Chevrolet Uplander Question: Why has gas mileage has dropped from 21 to 15 run great and air filter is clean
Are you checking your mileage in around town driving or a long road trip? Driving habits have more to do with than one would think sometimes.
have fuel trim ck it could be cause by a number of things and scan for codes
Replytomas e, June 07, 2012, 05:03Rookie
What exactly is fuel trims and what kind of codes should my mechanic check for? Thanks and God Bless
Replymilesauto, June 07, 2012, 05:31Master
It may not have any fault codes....Fuel trims are a way that the technician may be able to tell if for some reason the fuel control system may be making the system run a bit on the lean side due to perhaps a vacume leak or on the rich side due to a lazy oxygen sensor or a dirty fuel injector. This requires a good technician to dig for possible problems....best make sure you really have an issue first by checking your fuel mileage accurately on a road trip.