Hi all can any one out there tell me what sencor's work with megasquirt part numbers would be helpful, I see ome of the web site's they list the water and air temp sencor's as these will work but do you still have to set these up first.......thanks Gordon

If you go with the appropriate GM sensors, then you don't need to set it up first.
http://www.megamanual.com/v22manual/mwire.htm

If you use other sensors then you do.

Have you got MS1 or the MS2 daughter card?
With MS1 you can use a program called Easytherm to calibrate everything.

With MS2 it is easier and you can just calibrate the sensors from TunerStudio.