well i have been having horrible MPG, (around 7-8mpg, 90% highway/backroads, mazda 5 speed od, 4.9L dont know gearing, long bed, 31x10.50 AT's)

and i decided to try pulling some codes and to see what i got, did the key on engine off test, no KOEO codes, a few continuous codes,
this is how they read out


alright so after re checking so that i was confident in those numbers it came out to

(edit): found a site ( http://www.troublecodes.net/Ford/ ) this has trouble codes but in any of the list ect it never mentions the 4.9L f150, and it says 7.3 turbo diesel and villager, idk? does any of it match the codes for my 4.9l ?? im really confused since this is the first vehicle ive owned that was even new enough to have a computer, and have never dealt with codes ect.

522
522
1
327 (the list on the site above says this has to do with the EGR, witch would make sense since i cut my exhaust off about an inch and a half past the egr pick up,) still have found nothing for the code 522, or the 1..
327

i cant find what the codes mean any where and could use the help

 

So 522 is vehicle not in park or neutral during KOEO test or Park/ Neutral switch circuit open. I wouldn't worry about that one since you have a Manual 5spd.

And 327 is the EGR valve position sensor circuit bellow minimum voltage, or the differential pressure feedback sensor bellow minimum voltage. This here would be a good indication to bad fuel mileage and poor performance.

 

so with the EGR valve position sensor circuit bellow minimum voltage , or the other would that be because of the cut off exhaust? i cut it off maybe 2" past the egr pick up line, or is the EGR just not working properly.

 

Sounds like it may be the EGR causing you're issue. Not sure if the sensor and the EGR can be replace separately.