i was installing my new cai that i just bought when i realized that my iat was missing. anyway after searching i found it, it had fallen out and was still attached to the wire, anyway can i clean it with water, or will that screw it up, im looking for suggestions here.. thanks

I would use a contact cleaner and be gentle.

Or swish it around in a container of rubbing alcohol.

what can Dirty IAT affect?

The correct air intake temperature reading. Might run you lean or rich depending if it reads high/low/or fault.