Sorry to be a pain been searching but nothing to my exact needs and confused by fastchip website. standard 2002 172 vin=CB1N software version is 6400 and cal version is 5402. what maps can i install on my ecu also what do each one do and which is best? also what exactly is the difference between tottally writig the ecu and just installing a cal file? im just all bloodie confused now prob because im scared of messing up the ecu!! cheers guys.