I've been having a problem but been ignoring it now I can't. Well what was happening was that sometimes when I would stop to back up at work my truck would turn off. I was not really worried about it but now that I got the heads and cam on it does it at times when I come to a stop and while backing up. I got a live tune yesterday but it's still does that. On my way to get the tune I got codes 171 and 174 after I got the tune I got them again. 2 min later i'm approach a stop and the truck turns off. I got back tweeks somethings go to a drive thru turn off the truck and can not get it to come back on. I two foot it to 2k and finally get it to stay on that way. drive home for 3 hrs. Get up this morning and turn the key and its on. what gives? dirty maf or something?