My SES light came on the other day and went down to autozone and had them scan it. The code was a P0420 which has something to do with the Cat or O2 sensor on the drivers side. Not sure which the problem is so I bought the sensor but haven't installed it yet. I've seen some people saying the Cats are under warranty for 8years/80Kmiles. Will the dealership still replace my Cat for free even though I have a cutout in my I pipe? Or are they going to screw me?

 

ttt, anyone?