How do you find and erase Trouble Codes

[mR496]

always click the gas cap 3 times and you will ge good to go.

[Yetti]

I had my evap set a light twice now. both times the temp changed over 30 degrees while it sat in the garage. also it had less then half a tank of fuel. the purge valve on the charcoal canister should have prevented this. but I do believe mine is packed with mud so it doesn't vent in a timely fashion.
I drove by the dealer to clear them with a Tech 2 scanner. took about 5 minutes.