Hi-

I have previously posted a question on how to obtain the code since my engine light came on. I finally went to a repair shop and they gave me the code which is "P 420". They told me that they did not know what this code stands for and turned the check engine light off.

Does anyone know what "P 420" code stands for?
Thanks in advance for any help!


Laura
2001 GXE Silver - Stock

 

it's your cat converter. There is a technical service bulletin on this. The dealer should reprogram this for you. I had this problem and flashing the ECU didnt help, so they just replace my cat converter.

 

Thank you for the reply!

I had the shop guy turn off the light. Would I have a problem if I took it in for the warranty? or is this something I need to pay for?

Thanks Again!
Laura

 

Well, if you dont have the SES light on, then the dealer cant do anything. He told me not to clear the SES so they can check thier computer. Well, you SES light should come back on again in a couple hours or days of driving, so it's shouldnt be a problem.

It should also be under warranty since it's under the 80k emissions. Some dealers wont honor this, but some others will. I went to 2 dealers before they said they would do it for free. So just call around and ask.

Hope this helps..

 

Hey Laura, the PO 420 code refer to: Catalyst System Efficiency Below Thresold Bank 1, I think it might be an O2 sensor .
I erase the code the first time and it came right back the next day, so I replace the O2 sensor and it never came back, a 57$ cdn cure and 20 minutes for the install, good luck.

Cheers


AA

 

Laura, your best bet is to take the car to Nissan dealer, because these mom-pop repair shops can only repair flats. There was a TSB (technical service bulletin) issued for some 200 model year Maximas, where factory-programmed computer (ECU) is incorrectly "reading" the emissions components. Nissan dealer would reprogram your car's ECU but may charge you for it if you are out of 36K mi/3 year warranty.

 

I see... well thank you very much for the info. I greatly appreciate it!

Laura

 

I was pulling the sam code. My dealer flashed the ECU and it's been out. Hopefully it doesn't come back on.........

 

They flashed mine at like 16k, but it came back around 45k. So they just replaced the cat around 48k.

 

Hi doublea,
Which O2 sensor did you replace? My 2001 SE still has the SES with the P0420. I have had the PCU flashed already.