I have a stock 01 ranger 3.0 2wd automatic it seems i am going through a lot of gas a week what can cause it. I did a tune up when i bought the truck only thing i havent done is an oil change can that be why i am getting bad gas mileage oh yeah the air filter is a spectrum air filter not stock there but not dirty at all

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1999 Ranger XLT extended cab 4.0 engine 4wd and all stock for now