Serious answers only please. I have a 1995 Ford F-250 XL 5.8L 351 c.i. engine. My check engine light comes on periodically when I drive. When I bought the truck a year ago the gas mileage wasn't too bad, about 9-10 mpg. I've only put about 3,000 miles on it this past year, and now the needle drops just driving it across town. I work at a Chevy dealership, and I've worked at another Chevy dealer as well as a Ford. I've always done my own work on my cars and am currently restoring a 1967 Mustang, so I have decent knowledge under the hood. I scanned the truck and it has a stored code for EGR valve voltage too high (stuck open). How bad could this be hurting my gas mileage? It's $160 for the valve and sensor even after my discount, and being a college student that's a lotta $ to pay. I'm selling the truck and need it running perfect when I do. Please, serious answers only, and help is greatly appreciated!