Fuel Mileage Gone!

[Leveled F-250 SD]

Alright, my MPG fell off, only got 107 miles to a half tank and thats normal driving 65-70 mph down the highway. Any one got an idea of what it could be?

It's an 01 7.3 with 160K, stock intake and straight piped exhaust, Edge Evolution on "Extreme". The only code that I get is P1316, I know what it is, and I know that either I replace the UVCH harness or use the wedges (anyone got the Ford part number for the wedges?) but it doesn't seem to be running rough like it's missing or anything.

I am getting maximum of 18.2 PSI of boost at WOT. but cruising down the highway egt's are running around 700-750 with 3-4 psi at 65mph, egt's seem high to me cause usual was 600-650 with the same boost.

From what I can tell there is no excessive exhaust smoke, but I've noticed a small oil leak after the truck is parked in my garage, I cant tell where its coming from though. All I can see is a little bit of oil in the valley towards the back of the engine by the turbo, and thats it. After I finish here I will pull the IC tubes and see if I can get a better view.

I hope I've covered all my bases, but I'm sure I missed something. Any help anyone can give me on getting my mpg back up would be greatly appreciated.

Thanks
Rob

[ToMang07]

You probably have a boost leak. The oil leak is probably the turbo pedestal or EBV solenoid, but yo need to get in there and trace it to tell for sure.

[sethc24]

18 psi is indeed low for an 'extreme' tune. I hit 30 easy on mine. you have a boost leak for sure, check your exhaust up-pipes for leaks.

[renoduckman]

Leaky intercooler boots were causing my mpg drop.

[Leveled F-250 SD]

I was thinkin that the intercooler boots were the culprit, I'll be ordering a set from diesel site next week along with a boost leak tester. Thanks for all the input guys!