I have a 2005 496 h.o that is throwing a two beep alarm every minute and the tach bounces. Engine runs fine when alarm goes off........ Any ideas

Iac

Idle Air Control.. would'nt the motor rev up and down with the tach?

IAC is a strong probability, but I would not buy or replace anything without running it on a scan tool first.

If you have a 496, or any of the motors with SmartCraft, the Rinda scanner is some of the best money you will spend on your boat.

+1 I just did the Rinda thing and glad I did. Found a used unit in Oregon for $200 with version 1 chips. Found a set of version 4 chips for a good price and now have the complete setup for $260. Best money I have spent on my boat yet.