hi anyone know what could be causing 2001 blazer 4.3l vortec to stall out with a/c is on does it sometimes changed throttle postion sensor,idle air control a little stumped the truck has good pickup and runs fine.checked with codescout no codes the only thing that isn't coming up as checked is the evap system bought new gas cap,back to the a/c i hear a whistling noise when a/c cycles on and off anyone have any ides about this problem

 

Have you cleaned your EGR valve and throttle body completely?