Hello to all! Im new to this forum, but not new to the truck and performance world. Ive followed this site for quite some time and finnaly decided to become a member as more useful posts and help is done here rather than elsewhere. My problem has me stumped. I forever have read reviews on the rev x and its abilities to help stiction. I have a 2004 6.0 with 160 thousand kms, so 100 thousand miles. I have been having cold start issues as most have done in the past. It would smoke, and feel a miss, but not through a code. I installed Rev x and it seemed to work right away. I drove the truck about 100kms, so 60 miles, and punched it to pass someone, and y truck died. Went dead, no warning. It sat outside here in calgary ab, in minus 25 all day, From what I read, I decided to go after the IPR valve ( as I just had my HPOP, ICP, oil cooler, and egr done last week ) In the freezing cold, after 4 hrs, ( I know that took longer than most, but was my first time doing it and didnt have the correct socket ) we got it out and sure as #### the screens were clogged and one torn... So I replaced with a new one, and put it back together, and the truck fired right up even not being plugged in! But to my surprize, and fear, It ran like crap until temps got to 184* F. Any colder and at Idle it felt like it wanted to stall out, it would sputter, and still no codes eccept Exhaust backpressure code that went away after I hit the 180* temps. Does anywone know why the truck is running like this? My oil was changed with shell rottella T tripple protection Twice this week! Once cause I did the HPOP and then because I drove 2000 miles on a trip to Idaho to buy some sleds and when got back wanted fresh oil with the Rev x. Im stumped... any help would be great. Thanks guys