Hi im am new to the forum. I have a 03 ford explore with V6 4.0 sohc. It has about 125000 miles. I was getting really good gas mileage around 17 in town and 18-20 highway.Now MPG are all over 12,16,13.
I change the oil ragerly
changed: fuel filter, air filter, pluges, wires, and had ford update all the computer programming.

I have had some problems with hard starting and engine kind of surges when driving. I had a some truble with the pluges to put in some boshe pluges and it didnt like them had to go to motocraft. I think the problem might be the fuel pump but i dont no if that would give me bad MPG.

IF you have any Thought it be a lot of help

THANKS

 

You might want to check the EGR valve and system for excess carbon build-up.

 

Same problem after tune up on 2006 Explorer. New plug wires, motor craft plugs and fuel filter. Mileage went from 16-17 city, 20-22 highway down to 13 city and only 14.4 highway. Anyone know why this would happen?