Where is the ECU located

I owned my car for almost 6 months now, and i still haven't found the ECU. It's a 91 CRX Si. The check engine light has been on for the past 7000 miles, and it's been running fine,but I'd still like to know what code it is throwing.

Oops, I meant to post in the real forum, not the Off topic. Can a mod please move it?

in the pass floor bord behind a metal plate.