Hey, I have recently run into a problem with my 2003 gmc sierra 2wd 5.3. I have run three tanks of gas through the truck, all at different gas stations. My truck is otherwise stock except for a volant cold air intake. I need some opinions before I take it in and get a computer scan. Could it possibly be the cats, o2 sensors, or any other things that are common for bad gas mileage, could you post some problems. Thanks for the help.

cory

 

What type of "bad mpg" are we talking about here?? What are the city/hwy #'s

 

gettin hot here lately too. the heat could account for some bad milage. also low tires, dirty filter, ac runnin full blast 24/7 etc etc.

 

also a heavy right foot!

 

the ac isent going to affect your gas milage that bad

 

Ya I have run my AC once in the last two weeks. Im a windows down type of guy. I just cleaned my air filter one week ago. I dont record my gas mileage. I just try to get as far as i can on a tank. It may be my right foot, it just seems like I can watch the needle run to the E, and I dont drive that hard. I am pretty stumped.

 

Too much oil when you cleaned the filter? Maybe the maf needs a cleanin'.

 

how many miles are you getting to a tank?

 

I actually read in MotorTrend that driving with your windows down and A/C give you like 2% better mpg than if you drove with your window's up and A/C. It has something to do with drag created with the windows being down. The way to get the best mpg is both windows up and no A/C (Good luck on that one)

 

well its about 550 KM to a tank, so any math experts wanna figure that out. it did it before the clean air filter, and after as well. no clue