Rev_happy

My friend has a 2000 Maxima, and it stalls a lot at idle. he cleaned the throttle body about 4000 miles ago, and that cured the previous stalling issue he had. This new one is different he said, before if he would rev it up, it would then stall, now it just stalls at idle. Anyone have any ideas? Should we try cleaning the throttle body again? He has taken it to the mechanic but he cant figure it out. any help is appreciated, thnx.