Is there a tool or software program that can be used to plug into the ECU's to read and monitor engine functions, fuel mapping, EGT, etc ?

dude....... i took care of all of that... precision efi allready did the ecus... and mpg was up so was some snap in accel

http://www.rinda.com/

Is there also a way to confirm the # of hrs on a 500 EFI like there is on a 525?

I was told today that it is possible to tell actual hours of each 500 efi from the module ,need to find a Merc Platinum repair service ,they have the equipment to check, Any on Long Island?

The rinda tool listed above will show you actual hours. I have had one for three years now and they are a great tool to keep on the boat.

Thanks, good to know.

Not sure if works on the 500's but the Diacom Marine s/w is pretty cool. I use for my 496.

[QUOTE=Dock Holiday;2465722]The rinda tool listed above will show you actual hours.[QUOTE]

Can you do the hours @ certin RPM's with the Rinda and 500EFI?