1toncrwlr

I have the following set up:

07 LQ4 6.0 from a silverado 2500
LS2 intake, throttle body, injectors/fuel rails, & MAF
X-link converter to run the LS2 throttle body on the truck harness
block hugger headers

PTC th400 FRMVB

When you first crank the engine it runs perfect and will rev to the moon, then 5 - 10 seconds in it starts to act like its in limp mode - The computer is not throwing any codes

with the engine off I see a TP of roughly 18% and it will advance to 99.6% at WOT

with the engine running I see a TP of roughly 8% at idle but it wont rev past 25% or so

The engine will run for as long as you want and never attempts to die

any ideas?

VATTS removed from computer, abuse mode deleted

Thanks in advance!