Q: F150 ecoboost poor gas mileage

asked by on March 17, 2017

2012 F150 ecoboost poor gas mileage with E10/E20 (approximately 12.2 and 11.6 respectively) recently switched to premium and worse if anything (less than 11 so far). About a month and a half ago dealer replaced PCV, serviced throttle body and updated software. This was supposed to take care of overfull oil that had sharp odor. Oil is probably quart over full again

You should not see the engine oil get higher unless you have excessive fuel getting into the engine from a leaking injection system like a leaking injector. You should have the fuel pressure monitored when the key is cycled on and off and then on again to see if pressure goes down quickly. If you are losing pressure then scan the computer to see if it shows a cylinder that is misfiring? If one cylinder code is stored then that injector is most likely the one stuck open and leaking. Remove and check that injector. If leaking then replace it and then change the oil and filter.

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