I had p0420 and p0158 and I put in a warpspeed ypipe and a new o2 sensor and the code went away. A couple days later 420 and 430 came. I have no idea why? Is it that the ypipe is highflow and the computer isn't reading it? And it's a 01 Cali spec so I still have one pre cat. Any way to get rid of code

 

gut the precat

 

If I gut it, do you think it's going to go away?