98 Expedition 5.4l 203k miles
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Joined: Mar 2018
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98 Expedition 5.4l 203k miles
Been driving this vehicle for a few weeks as I just purchased. It’s in great shape for a 98.
Gas mileage is horrible. 9 mpg. I think it should be 12ish.
Tire pressure good. Injectors cleaned this year. Oil has been changed regularly. No check engine light. KN air filter. Engine runs great.
Any ideas?
Gas mileage is horrible. 9 mpg. I think it should be 12ish.
Tire pressure good. Injectors cleaned this year. Oil has been changed regularly. No check engine light. KN air filter. Engine runs great.
Any ideas?
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Joined: Jul 2006
Posts: 7,555
Blended fuels?
OE tire size?
Could have a tailpipe emission (dyno) reading taken, but I'd think if it were running rich the monitors pre and after cat would set code. Blended fuels can drop MPG a tad. Possibly pressure test the cat flow/efficiency given its mileage. Base engine issues can affect mileage without affecting overall driveabilty, or set code...
OE tire size?
Could have a tailpipe emission (dyno) reading taken, but I'd think if it were running rich the monitors pre and after cat would set code. Blended fuels can drop MPG a tad. Possibly pressure test the cat flow/efficiency given its mileage. Base engine issues can affect mileage without affecting overall driveabilty, or set code...
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