i just redid my wires and plugs and cleaned my tb, (u dont want to know, very black on bottom, had to use an snap-on sock (LMAF) to get it clean )
but i am still getting lower than average mpg on freeway ( about 17 MPG)
stock every thing but before intake before mafs is an high flow air filter.
a flow student told me it try to reset the pcm long term fuel data.
but i don't know how.

 

It's almost 99% not a PCM setting unless some PO screwed with the programing. There is nothing you can do to your PCM other then sending it to a pro tuner.
17mpg freeway is low unless you are really stomping on it for some reason.
Unless you have changed tire size you should be able to get your mpg's up.
First thing, do you have any codes, most of the stuff that will kill your mileage that bad will throw a code. When you turn the key on make sure your check engine light comes on for a second when it runs through it's self test. The bulb might be blown. If it is take it to an auto parts store that will read them for free like autozone or O'rilley's. Then come back here with what they are if any. Don't buy any parts.

Your high flow air filter is suspect, most of them use oil that can clog your MAF sensor. You can clean it with a can of MAF cleaner from the parts store. Follow directions on can. You said gummed up TB and high flow in your post so this immediately comes to mind.

Oh yea, how's it running, surging, high or low idle, stalling on a hard brake any of that good stuff?

Go to the BF homepage and in the Google box enter low mpg and start reading.
Again don't buy any parts, come back here with things you think may pertain.

Someone here will respond.