Idle speed extremely low... please help!

I have a 92 Honda Prelude SI. I recently changed the catalytic converter and O2 sensor. Initially, the car ran great, but now it is running so rich that the spark plugs foul with black carbon within minutes. The idle is extremely low and irradic. What could be wrong?

I would try cleaning out the throttle first. That sounds like a problem I had with my car. Also try resetting your ecu by tking the battery lose for a few minutes. HOLLA!