Bad gas mileage!

[caseywan]

A few weeks ago I was out driving and had some stupid kid in a cavalier messing around with me so I just had to show him up. I was going about 25 and down shifted to 1st (yeah, a little to low) and let it go up too high i think about to 9k. And then the engine was kinda sputtering and rpms were going up and down when I gave it any gas at all. So I pulled over in a parking lot, popped the hood to a take a look. Didn't see anything up top or anything leaking on the ground so I started it back up and it was just fine, no problems at all after that. But it does seem like I have been getting a lot worse gas mileage since then, like a little over 300 miles to a tank highway, and not even 300 street. I do have a chip and 80mm MAF that didn't really seem to affect my mileage for the first month or so that I had them.
Anybody have any idead what happened?

 

[Blue-By-U]

I would start by running codes. You can do it yourself (search for a link) or you can take it to Autozone.

 

[jaded93atx]

If it was stock then 20 miles to a gallon driving in Chicago traffic with accesories on isnt bad, add on a 80 maf and the occasional redline run and 20 miles a gallon seems exceptional. If youre concerned about mileage then drive 55 and steer clear of the smoke shows.

 

[caseywan]

When I first pu on the 80mm MAF and chip, I got about the same gas mileage as I previously had, 375 or so highway and 325 street.

 

[SHO-93-ATX]

damn, same prob with me, i got the same mods. but im only gettin 230 miles per tank in country atmophere, but i start the car like 12 times a day. and take a few short trips to lunch and to work coming from school. When i actully drive straight freeway, i get 300 per tank, and i driv e a 300 mile trip every other month. and thats just to the one location. i still havent figured it out.

 

[Electricat]

Lower MPG may just be due to the weather getting colder of late.....cold air is denser, which requires more fuel to get the proper A/F ratio, resulting in more fuel burned.

Also results in your car going faster, WOOHOO!!