can a liquid be put in a catalytic converter to unclog it?

no...this is a chemical reaction using rare-earth elements....best you're gonna be able to do is run it long and on a high-demand RUN....willl burn off any hydrocarbons...it wants to take the poisonous CO gas and change it into CO2 nitrogen and water vapor...any additions will slow or stop this from happening~

try a tankfull of the higher 93 octane...burn it HARD on a long drive up to Cleveland or such....where it gets to see a 65-75 Mph drive for an extended period to "burn it off"...you might say~

how many miles are on the car? The car seems too new to have issues with the converter unless something else is wrong with the engine.

thanx for tha answers. I live in san marcos tx. imma fill tha tank wit tha"good" gas an run it to San Antonio. But I let u know how it goes. Got my fingers crossed.........

just be warned your check engine light is gonna come on doing it this way for your o2 sensors if you don't want the light ease your way into 93 octane it wont mess with your sensors that way