146 miles and 3/4 tank gone...

[moogvo]

This is absolutely driving me crazy. Something is killing my mileage. I have no codes and I am getting 9 to 13 mpg. It doesn't matter whether I drive it like I borrowed it or drive it like I stole it. Same either way. There are no codes. The vacuum is fine and I can't find any leaks, the cats are fine, I am about to run this thing over a cliff! It is an 02 explorer sport 4x4 all stock. With an 07 Mustang 4.0 with 30k miles.

Any ideas? ANY AT ALL?!?!

 

[acschilling]

Perhaps your O2 sensors?

 

[moogvo]

I do have an o2 reading 0.0v most of the time. It will occasionally jump to 0.3 and then drop back to 0.0. It is the last o2 sensor behind the cats. That is a possibility, although a mechanic friend of mine told me that reading could be normal.

 

[my98nnj]

O2's behind the cats do nothing to fuel trim, they only monitor the cat's efficiency.
The front o2's are what look at a/f.

 

[moogvo]

Yeah... the fronts look fine.

 

[gmanpaint]

Possible it is the Fuel Regulator.

Check to see the vacuum line is still attached.

Check for fuel in the vac line at the tree. Replace if fuel is found.

 

[acschilling]

I know I'm only roCkin a 92, ten year difference, I was getting the same kind of puzzling, ****ty gas mileage...changed the one O2 sensor and noticed a considerable difference. How many do you have....4?

 

[moogvo]

I will check the FR vac line. I have 3 o2s. One on each manifold and one between the last 2 cats. Odd, I know.

Y'Know... I bought this thing, really as a Bronco II fan. I thought "Really, how much different can they be?", now I get that there would be more in the way of emissions and computer control, but mechanically, I thought it would be pretty close.

BZZZ! WRONG! I got 26mpg outta the BII and kinda hate that I sold it!

 

[koda2000]

possibilities that come to mind are O2 sensors, fuel injector(s), FPR, MAF, coolant temp sensor, air temp sensor, air filter. have you run a finger inside your exhaust pipe or pulled spark plugs to check to soot? there shouldn't be any. another possibility, where i live, is bad neighbors...

 

[Seanmarty93]

possibilities that come to mind are O2 sensors, fuel injector(s), FPR, MAF, coolant temp sensor, air temp sensor, air filter. have you run a finger inside your exhaust pipe or pulled spark plugs to check to soot? there shouldn't be any. another possibility, where i live, is bad neighbors...

KODA2000........You got my laughing pretty hard at the "BAD NEIGHBORS" comment, maybe its the couple of beers I just drank, but I can't stop laughing at your comment. I'm just picturing this poor fella under the hood scratchin his grease soaked head, trying for the life of him to figure out his fuel consumption issues. He finally has enough for the night, goes in to retire for the night, and then here comes the neighbor runnin around the corner with a 6' hose and 2 5 gallon gas cans!!!!!! :scratch: