Decreasing gas milage [Archive] - GrandAmGT.com Forum

PDA

View Full Version : Decreasing gas milage


TFA
08-18-2007, 02:49 PM
My gas milage has been slowly decreasing over the past 2 weeks or so. I recently had my injectors flushed, oil change (still about 2K left before the next one) , had my fuel filter replaced a few months ago, and i have a K&N cone intake. My tire pressure is good. What else should I be looking at? Im also loosing a but of low-end acceleration and torque

AaronGTR
08-19-2007, 07:41 AM
wrong section. This has nothing to do with performance.



It's really hard to diagnose a fuel milage problem because a lot of it depends on how you drive. You can't simulate the exact same conditions on the road day after day and week after week so there is no way to tell the milage changes aren't just because of your driving. The only way to tell is to test it on a dyno under a constant load, or if you have a large sudden drop in miles which would usually be an indicator of a significant problem and sometimes accompanied by a check engine light.

silvercoupe
08-22-2007, 08:24 AM
How many miles.. any symptoms? hard starts when warm?

the common thing on these cars is the front O2 sensors needing replacement, or Fuel Pressure Regulator going bad. these, especiallly the O2 sensor will make the mileage go gradually, like its happening to you. do a search "oxygen sensor" or "o2 sensor" in this forum.. you'll see what Im talking about.

but again.. any other symptoms would help.