You maybe running lean. I have had that the stalling problem ever since I install my new MAF. I know it is ruinning lean because of the OBD-2 and if you check the voltage across the 2 wires on the MAF (can't remember which 2, check proflow.com) and it should read between .7 to .9. I recommend getting the OBD-2 scanner with the group buy, best investment.
Cheapest exhaust mod is replacing the resonator.