Ok. I'm not only a newbie but also not a car guy. I have the 0420 and 0158 codes on my 2k1 Maxima(Meridian Edition). I have read thread after thread about the 0420 code and I am still lost as to what to do. I have no idea if the ECU was flashed prior to my purchasing this car a couple weeks ago. Took it to the dealer because I also have the abs,tcs,slip lights on(they want 2200 $$ to "fix" that!). Anyway, should I and/or do I need to gut or replace the precats on my car? It has 91k on it. I'm also not sure of HOW to gut the precats and do I need anti-foulers if I do that or something else? Would a Y-pipe be better? I don't want to spend a ton of money but I don't want the engine getting screwed up on me either. I would appreciate your advice since I am hopelessly lost here. Thanks!!

 

For the 0420, just replace the cat for bank 1,

 

Thanks! Shouldn't I eliminate all the pre cats so if they deteriorate they won't destroy the engine?