Whats up with this??

[bronx79]

I know this has been a topic a million times but.... My fuel mpg's have gone from about 13.8 ish to 10.5 ish in about five weeks!!! is that because of winter fuel or do me and my truck have a prob? im not expecting better than 13 or 14 with an 2005 HEMI but this truck has new plugs, cleaned TB, long tube headers, cold air intake and i don't drive like im fleeing from the law either.

I'm just curious if its just the way it is?

Any insight would help guys and gals,

Thank you!!

 

[ramhunter9]

Could be winter fuel and the weather

 

[WhiteExpress]

You might need new O2 sensors.
I know on my '01 when they started acting up, my MPG dropped like 4-5 MPG almost overnight.

 

[bronx79]

You might need new O2 sensors.
I know on my '01 when they started acting up, my MPG dropped like 4-5 MPG almost overnight.

i replaced to downstream o2's this summer but could the upstream two be causing me probs?