I have an 08 Suburban with VIN "O" that experienced lifter failure. We did a complete DOD delete (new stock non AFM Camshaft, new lifters, valley cover, all gaskets, new ECT and Cam Sensors, new plugs, etc). Before starting I took the factory tune and turned off DOD using an HP Tuners MPVi2, didn't make any other changes at all. It has extreme trouble starting and once started idles between 550-750. There is no noticable sounds from the engine at all and no codes being thrown. On a few different test drives it seems to run fine with the exception of feeling like it is only running on 4 cylinders. On flat ground it has good power but at slow speeds going up a hill it barely wants to go. Also, when at WOT, there is a massive growl (sounds like air being sucked in) under the hood and it takes forever for the car to gain speed. Once rpm's reach 3500+ it runs just as it should and has plenty of power. The only thing I have adjusted so far was the VET based off of the LT and ST fuel trims when test driving. This did very little to help in any aspect. The car does seem to start easier when cold but once warm, it nearly runs battery dead before starting.

I did check the differences in the cam (old to new) and the lift is within .010 and the duration dropped from 192/194 to 190/190 which I don't believe should cause this big of an issue. The only other thing that may be important is that the LT & ST fuel trims seem to be staying within +/-7 on bank 1 where they are all over the place on bank 2 (+/-20). I did a compression check on all cylinders and tested the coils as well. I am completely lost on this and would greatly appreciate any help. This being our main family vehicle I'm pretty desperate to get it running correctly again.