so my brother has an 06 lly, basically lbz. 2 weeks ago he installed a power steering cooler and hot pipe. the next day he got a p0698, p0106, p2563, p0700, u0100, and p003A. so far we have tried switching ECM's and same thing. then we tore apart the ECM connectors and cleaned them, runs better and the p2563 code hasn't came back. I've also tried cleaning the 2 big connectors on valve cover still with no luck. on my scan tool the codes will say passed/failed most of the time. every so often with messing with everything i can get them to pass then can clear them. friday had the codes cleared, ran the truck for a while and did like 15 start ups and drove it around the block without codes, then yesterday he got not even half a mile from the house and all codes came back and back to limp mode. we've also check for ref V at map and sometimes it 2.2-3V then go back to it 5 min later and 5V. I'm at a loss here guys, what should I look at next??? he's bout ready to trade it off cause of this.
