help!!!very bad fuel mileage

[pearlwhite97gt]

hey all my car is getting 13.5 mpg i drive the car in the city shifting under 2600rpm i have a k&n full exh w/o cats the car has always done atleast 15.9 in the city and the past couple of weeks its been dropping to were its at now i was looking at my o2s and i see bank 2 switching from .1 to .9 volts rather fast but bank1 is switching slower and barely going over .55 and no cel or codes what do you think bad 02 sensors?

 

[Lifter583]

Gave the MAF and throttle body a good cleaning ?? I also run Sea Foam in the gas tank every 1k to keep the injectors clean...K&N's are good at coating the MAF with oil...and giving a false reading of air flow...

 

[DarkFireGT]

Maybe a bad tune? You should be getting around 20 or more if you're shifting that low.

 

[pearlwhite97gt]

thanks will try cleaning the maf tomorrow im running the 93 performance tune with the maf curve at -4% on the diablo sport tuner.. i regret buying the k&n system after seeing the other kits like the c&l but ohwell thanks guys i will keep you posted!

 

[SpartaPerformance]

Darkfire is right, I average 22 mpg with 60% city driving. Is your air filter dirty???

 

[GOLDENPONY]

Dark Fire is right, I average 22 mpg with 60% city driving. Is your air filter dirty???

Unlike carbureted cars, in computer controlled cars a dirty air filter will more affect performance than fuel mileage.