Ok changed from a megasquirt back to stock ecu for the time being because cold tune hasnt been sorted 100%. Only thing now is the car idles at about 1500 rpm then slowly drops back to 900 rpm or so. No idea why this happens. Also the car doesnt seem to rev too fast anymore. Is this normal for the stock ecu or have I got too used to the MS?

it will depend on a number of things, timing, what cam you have in it, weather the stock computer can handle those things

also remember you need to let the car idle for about 15 minutes to allow the computer to reprogram itself.

my advice is disconnect the battery for 30 minutes, attach it again and let the car idle for 15 minutes. by then it should be isdling smooth and between 500-1000rpm (depending on cam - my NC is stock and idles just above 500rpm)

Since it's iding higher than normal, have yo checked your ISC. Their a common problem on falcons for getting dirty, causing them to idle rough or high. Clean that out and try it again. See what it does.

when i cleaned my ISC module i spreayed degreaser in there for over 20 seconds and it leterally poured out black for the whole 20 odd seconds