Help Please! Low Milage problem

[Vi3tBoY1029]

So i just recently fixed my car that had idling problems for about 2 weeks. i had lots of people come by and try to vag my car. Now the car works, but i only get about 220 miles for a full tank of gas. The previous owner said that he got about 350 miles on a full tank. i am pumping 91 octance, but i still only get about 220 miles. So i was wondering if when my car got vagged, if it disturbed anything in my car? Please help me. I cant stand having to pump gas so often. Thank you in advance for anyone who can have some input. Thank You

[andry]

please check plugs, wires, air and fuel filters are good and clean.

[Revolution02]

It could also be your driving style. Do you have a heavy foot?