My 2001 Altima (4 cyl w/90k mi) is periodically stalling. I had the EGR valve/gasket, new plugs, distributor cap & rotor replaced and also a fuel injection cleaning and it still is stalling. The battery is new also. The dashboard lights come on and it does start back up. Sometimes it will stall a few times consecutively and then I have to rev it. If it sits for a few days it seems to be okay, but if I use it more frequently, especially on short trips, it tends to stall more. Any suggestions?