6.0 newbie, a few questions.
Hey guys, I've had my 2006 6.0 powerstroke automatic, 4x4 crew cab short box for about a year now. About four months ago I was having head gasket issues, got new gaskets and arp studs installed, as got an egr delete kit while it was in the shop. Sense getting it back, the truck alright, but it doesn't seem to be as strong as it was when i first got it. when first purchased it had 156k km on it, now it has around 164k km (about 100k miles), starts a little rough in the mornings. One major difference is the milage, when i got the truck, i was getting around 16 mpg and around 18mpg on the highway. now i get around 12mpg at best, highway or not. when first purchased i could get around 700 km to a single tank, now i get around 550, which is a brutal difference if you ask me. the truck also makes a strange whining noise when it accelerates, stops when i let off the trottle. truck also shudders slightly when accelerating from a dead stop, it stops shuddering after a few feet (rear end possibly?) d up a scantool from canadian tire. got the following codes: p1703, p1780. i hope this isn't too much, perhaps im just paranoid about something going wrong again. any ideas?