2006 2.3 won’t stay running
 

My 2006 Mazda 3 2.3 will run sometimes seems fine then will die on me and then won’t run will turn over then shut right off or some time not turn all the way over I have replaced the throttle body ran different code before for bad TPS didn’t fix it then started throwing codes p0421 and p2177 I have replaced the MAFS and does the same thing I think my CATS are clogged maybe anyone know anything about this happening