my service engine light was on. I took my max to autozone and they pulled the code P420. catalyst below threshold bank 1. They said it might be the oxygen sensor before the cat converter. But they weren't real knowlegeable. They cleared the error. I am waiting to see f the light comes back on. Anybody know what a p420 code is? If it is the oxygen sensor what problems will this cause. The light has not come back on yet but I have only driven about 15 miles.

 

O2 Sensor Bank 2. I just had the code pulled last week. Turned off the light, but it came back on 4 days later.

 

my light came on last week and i had autozone pull it for me. it was ignition coil misfiring and they cleared the code. when i took it to the mechanic the next day they couldnt find the coil and since then my car has been driving fine. i kinda wish autozone didn't clear it so i could pinpoint the (future) problem. I'm not sure when your light will come back on. I've driven my car 50+miles no light yet.

 

nissan has a tsb on the code p0420 o2 sensor high voltage. the fix from nissan is replace both rear o2's and re-program the ecm. i just had the same issue with my 02 max