2004 CHEVY 3.8L WARM START STALL/STUMBLE

I HAVE A 2004 IMPALA 3.8L, 105K MI.COLD STARTS PERFECTLY NORMAL AFTER GETTING TO NORMAL OPERATING TEMP. ,AND CAR SHUT OFF FOR 30 MIN TO ABOUT 1 HR,CAR WILL START BUT STUMBLE AND SOMTIMES STALL BUT WILL ALWAYS RESTART, NO OTHER DRIVABILITY ISSUES CHANGED VERY DIRTY IAC.CLEANED MAF AND EGR OF COURSE NO CEL CHECKED FUEL PRESS,AND REGULATOR ALL NORMAL.LOCAL MECH SAYS POSSIBLE INTERMITTANT CRANK SENSOR BUT I'VE RED CAM SENSOR WILL CAUSE WARM START/STALL AND IS A LITTILE EASIER TO CHANGE ,IF CHANGED MUST A RELERN BE DONE AND HOW. THANKS FOR ALL HELP PETE

you know, you might replace a lot of parts before you get it right. Before you throw a bunch of parts at it, (which is called the "shotgun" approach) yu should have the vehicle scanned. Scanning the data stream when the car acts up will be the easiest way to find out what the car is doing. It might be a fuel issue. It might be a TPS error. It might be either a crank or can issue. Recording the data stream will show you what the engine was responding to when the problem occurred. There are a lot of parts you could replace before you luck out and guess the right one. Or maybe not... you might replace a lot of parts and still not get it.

If you can't get a scanner that records the data stream see if you can find a shop that will do it for you. You will have to pay for their time and equipment but it may be cheaper that replacing parts that you didn't need.