Air filter
 

I've got my dad's 2001 . I put a new fram air filter in it because the filter moniter thingy showed 35% useage and my mpg's dropped , but the filter looked new. So i put a new in it and resetting it after a couple miles it shows 35% again and mpg's are still low . Is there a problem or am I buying <bad> filters ?

I'm not a big fan of Fram filters, but I doubt the quality of the filter is the issue here. When you say the mileage is low, what exactly are you seeing?

I ditched the factory airbox on my 2000 the 2nd week I had the truck, so I'm not the best one to comment on what's normal for the filter minder.

I used to get 21 driving 65 to and from work . Now it's down to 17.5 . What do you suggest if I was to ditch the stock air box ?

first clean the intake air temp sensor then the map sensor
if that dont work try and buy a new IATS ,it could be your injector need to be replaced or cleaned. also a failing VP44 can cause low mpg

Look for a boost leak first. Thats the obvious answer. Have your EGT's gone up since the boost level has dropped? How many miles on the truck?

I have found the filter minders to be fairly consistent, but a stronger engine, or one with mods will suck enough air that even a brand new paper filter will cause enough restriction to pull down the minder. Above a certain power level, besides the filter, the airbox and its inlet through the fender will be restrictive too.

I don't know what part of the country you're in, but the winter blend fuel would explain a drop in mileage like that.

Get you a Big Honkin Air Filter (BHAF).
I put on a BHAF and removed the muffler. Mileage jumped 2 mpg around town.

[laugh][laugh]ok...............

ya its like when you "put a 4" exhaust on you will see a 500 rpm drop" [duhhh]

If you are saying the mileage dropped after you installed a new air filter over a 35% blocked one something else has changed, maybe winter blend fuel etc.

I put a BHAF on mine in 07 and drilled a hole for the filter minder in the top, it has never budged so far and the filter is still relatively clean by sight.

I'd bet youre into winter fuel.

What ECM codes have you gotten?