I recently changed my car back to (mostly) stock, I flashed back to stock tune from RR racing tune, installed stock intake tubing from RR racing intake, and stock midpipe from Tsudo which deletes the secondary cats. Before the tune I didn’t have any CEL and I was running the tune for about 5 months before I flashed back to stock. After a couple weeks my car throws up a CEL, P0420 and P0430, “Catalyst System Efficiency Below Threshold Bank 1 & 2” does anyone know why? I’ve replaced the passenger o2 sensor on the secondary cat only because it was rounded, but still the CEL occurs even after clearing codes for the 3rd time.