Lexus: How do I reset the computer on 99 RX300

Hi,
My check engine light is on and I think it may have been due to an extremely
dirty air filter.
Now that I have replaced the filter, I was wondering if there was a way to
reset the computer to see if the light comes back on? I know in my old ford
I could just disconnect the battery. Can you do that with the Lexus?
I don't want to go pay a diagnostic fee if it was just the air filter.
Thanks