HELP! TERRIBLE GAS MILEAGE!! What can it be???

[WINSTON]

So my 2002 v6 has been getting around 16-18mpg on mixed driving for the past month or so. No idea why?? It has 104k miles.

The CEL came on about 6 weeks ago. Pulled the code "left bank lean"....never looked into it as it the CEL went off after a week. Though I looked on the forum and saw that it could be the PCV valve or O2 sensors.

What do you think could be causing the terrible gas mileage? Any and all help would be appreciated.

Ordering plugs and o2 sensors to be replaced as I know it hasnt been done in a while. not sure if that would help fix my issue.

 

[Right on the Mark]

What where you getting for mileage before. My 2000 V6 with brand new motor does 25mpg 100% highway and around 16-18 around town with some highway mixed in.

 

[WINSTON]

What where you getting for mileage before. My 2000 V6 with brand new motor does 25mpg 100% highway and around 16-18 around town with some highway mixed in.

I was getting around 21-22 mpg. I could tell bc I reset my odometer after each fill-up. Now I am going around 280 miles when my fuel light goes on (which is around what 1 gal remaining so burned through 17 gal.) Prior to that, I was getting over 350 which is around 21-22 mpg.

I drive the same route every day to work. So I am surprised to be seeing this significant drop the past few weeks.

 

[jolinc01]

Maybe replace the fuel filter if you haven't lately.

 

[PetesSweets86]

I was getting around 21-22 mpg. I could tell bc I reset my odometer after each fill-up. Now I am going around 280 miles when my fuel light goes on (which is around what 1 gal remaining so burned through 17 gal.) Prior to that, I was getting over 350 which is around 21-22 mpg.

I drive the same route every day to work. So I am surprised to be seeing this significant drop the past few weeks.

even my 2000 V8 gets 350-400 miles to the tank on Chevron Premium...that royally sucks man, hope you find the problem