2013 silverado 1500 6.2l. As it gets warmer outside, typically +80° my truck has a cold start issue. Itll initially startup just fine, hit high idle rpm then immediatly drop rpm, start to labor and chug with rpm bouncing around for 3 to 6 seconds. Kinda reminds me of a small engine being choked when warmed up. If i pull battery cable and reset ecu, itll start fine for 3 to 5 weeks. No check engine light. I also get inconsistant engine performance.
Ive changed, maf, map, crank position sensor and cam sensor, knock sensors, intake gaskets, fuel injectors, fuel pump, spark plugs, checked plug wires, new throttle body with tps. And changed upstream 02 sensors. Only run 91 octane.
Installed k&n cai and removed muffler. Any ideas?
I did have a code for low voltage on throttle pedal and changed pedal assembly

 

throw the CAI in the trash. 91 octane is a waste of money.
All those parts you threw at it were OEM right?
What do your fuel trims say?