SES question

[Schweppe23]

My car is throwing the code P0420 which says bank 1 catalast efficiency below threshold. Now this came on 2 minutes after i OVERFILLED my gas tank and spilled down the side of my car. I also had borla and hiflow cat on prior for about 1000 miles so i dont think it was that. Let me know what you think.

Thanks,
Pat Lavanty