Poor Mpg and rough idle on 2004 F150 5.4

[Jeremy]

When I bought my truck a year ago, I was averaging 18-21mpg and then it dropped to 11-15mpg. Since then, I have put in a K& N air filter, new plugs, new fuel filter, ran sea foam through the brake booster line and just recently put in new cam phaser solenoids for the rough idle and ticking. I am lost, I have no engine lights on, but when I get on the gas at times, there is a hesitation and chokes out for a brief second. Once it gets up to around 50mph it was to run like a race horse.
Can you please help

Topic

[college man]

see if this link helps.

http://www.ericthecarguy.com/faq/finding-and-fixing-the-causes-of-poor-mpg

[Harold Layne]

I have an ’06 and it doesn’t respond well to stomping on the petal. I always attributed the lag to it not having an actual throttle cable. As for gas mileage, my story is the reverse. I switched my tires from coopers to hankooks, and started running mobil one high mileage full synthetic ($24 for a 5 gallon jug a wal-mart) and changed the fuel filter, and my mileage jumped a good 3 miles to the gallon on the highway.

[Author]

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