WHATS GOING ON WITH MY mpg???? please look!!

[azmattaz06]

OK so lately I've been noticing my gas going pretty fast so has my brother and mom (I've been letting them drive my car) and my information center thing in the dash has been out.. Well anyway last night i replaced the bulbs in it and saw that it said I'm getting 11.6 MPG... That's terrible correct? my gf has a GTP also and she's getting 20 MPG and my cousins GTP gets 24 MPG.. I recently did a oil change and a spark plus change in the same night and still hasn't helped actually has been going down more.. any idea what could be causing this? I'm thinking plug wires and fuel filter next.. what else could help? cause that's pretty sh**y gas mileage.. Thanks guys

 

[cerick08GP]

20 mpg is pretty spot on IMO, 24 mpg if you do a lot of highway driving. The front O2 sensor has the largest single effect on mpg, I’d spend money on that before plug wires. Not to mention unless you’re mis-firing they won’t help your mpg at all.

PS. What plugs did you use?

 

[TorqueAutoMotiv]

Front O2 sensor fuel filter Also hows it running lack of power or anything

 

[azmattaz06]

It's actually got all the power still.. Besides the coupler going out which i dont think has anything to do with MPG.. I'll check out that 02 sensor.. Also the plugs were some copper NGK's..

 

[Vegas~Blown]

vacuum leak? the tee under the blower snout is known to crack with age.