2004 maxima won't start after engines warm
 

Hey guys was hoping someone can help me out here,
The problem started when I replaced the battery that went bad. The car starts fine when cold but After its warmed the idle drops to 400-500 rpm. If I want to restart it I have to rev the engine a few times. I've tried disconnecting the battery for twenty minutes and reconnecting it again. I even had a mechanic replace the two crankshaft sensors. Any ideas?