2014 Night Armor Xterra Pro-4X 6MT
Join Date: Mar 2013
Location: Downey, CA
FWIW - I have LT headers (DT) and magnaflow high flow cats and do not get any codes. Only time I did is when one of the O2 sensors touched the heatshield and blew the fuse. However, NONE of those several codes were the 0420 (driver) or 430 (pass)...after I replaced the fuse and reset from reader, they went away. I know this isn't what you are getting, just mentioning that in the last 3 years or so, never had a cat code running this setup.