Ok I have an 4.8L trick turbo kit Silverado. Fast LSXRT intake, fast rule rails, fuel injector clinic 775cc LS2 injectors, flex fuel pump and module, 3" exhaust no cat.
Last couple of weeks I have been having problems. The truck drives fine. Wide band is showing it stays at 14.7 at cruse. When I come to a stop light the 2-1 down shift seems to jump above 1000 rpm then when I come to a complet stop it the RPM drop below 500 as if it's about to stal out then returns to normal. It has actually stalled out on me a couple times. It dosent do it every time tho. It seems to do it quite randomly. I am pretty much pulling my hair out trying to find the cause. I know the LSXRT intakes are know for leaking so I have gone threw it and haven't found anything. I replaced injector o-rings, and every possible seal on the intake. I have checked plugs and wires. Fule pressure is good. I retourked the turbo manifold to the head and have checked ever bolt on the exhaust. I have checked ever vacume hose. Check valve on the break booster is good. Boost gauge say it's -15 vacum at idle. I have logged it with hp tuners and it seems to be all ok. It is also Turing my box side black as if it's running rich. Any suggestions. It was originally dyno tuned and worked perfect for about an month befor any issuse.

 

Is it possible to post the tune file and maybe a log file of you driving it and maybe something could show it self there.

Never hurts to have more eyes on it.