P0420 Nissan - pathfinder

Question

P0420 AND P0430 06 NISSAN PATHFINDER

Answer 1

most likely the catalytic converter is bad is there is not intake leak and other issues.

you can try to do an intake flush and use 91 octane from Shell and see if that helps.

if you use low octane fuel that is the #1 cause of the catalytic converter going bad, if there engine issues like misfire or burning oil