Bowlin5150

Good Evening. I have a 93 5.0 LX conv. and I have been battling a gas mileage problem ever since I put on a flow master exhaust system. I didn't do the job a muffler shop did. My mustang includes a MACH 5.0 air ram, 14'' dual Flowmaster mufflers with in increased size no more than 3 inch tail pipe. Underdrive pully kit, poweraide throttle body spacer, K&M Filter, 303 gears, and possi track in the rear end. I have had a tune up, replaced egr valve, its sensor, and solenoid. O 2 sensors have been replaced. The upper intake manifold gasket replaced. Mass Air Flow sensor replaced. I am still having problems with the gas mileage. I went from 19 to 20 in town down to 13. I have talked to other people in town and one person is telling me that the computer might have to be replaced or re-flashed. something about the ROM memory might have been erased due to the welding job done on the car. I was told that sometimes the energy from that might altar the computer. I am going to talk to a ford guy exp. 25 years and he's going to throw it on a scanner. If anyone else has had the same problem or has any info. Please advise. I ain't drivin no import for good gas mileage. I want my pony back. Oh BTW it has great power and driving force and I don't think that the four cats that i have on it are blocked. Thanks.

AdderMk2

your mileage dropped because your probably driving like a douchebag now...


ease off the go pedal

Tony71502

+1 Adder... haha

He welded a catback to your car? Even still, that causes no computer problems.

Just run koeo and koer codes yourself.

aleXander2648

I get around 20-25 in my car but then again it weighs about 1000lbs less than a fox lol

Tony71502

I get 21.5 mpg in my car with a cam, 3.73's and longtubes.

Btw your car's about 600# less than a fox.

Bowlin5150

Even when I had stock mufflers... If i was driving it hard i would still get 17 out of her. I even be puttin this thing in neutral on down hill courses. I even unplugged the MAF so the computer would run off then BMAP. Any other ideas other than being a duechbag. <----SP

Bowlin5150

I used to have an rx7 2nd gen gtu stock. But couldn't afford 5 pt on my record with my stang and maz. and i know how light those cars can be. but i'll still take yea in the long run. lol. well maybe....

FivePointOhh

plug back in your maf, douche. also did you run codes yet? maybe o2's are bad and that will kill your gas mileage. so will not using yoru MAF if you have a MAF car....

Tony71502

Another suggestion that is critical and often overlooked.... what's your tire pressure at? Go make sure it's at the proper psi.

Five0hFox

I 2nd plugging the MAF back in.