I got my code scanner from EBAY today ($35). Plugged it in and got code 0420. Then it reset my ECU. Cool! SES turned off.

Code 0420 is "Catalyst System Efficency Below Threshold (Bank 1)"

WTF does that mean? What do I need to replace? If it aint slowing me down or hurting my MPG, and my SES light is off, should I replace anything?

Thanks!!

 

I got that exact same code. MY SES turned on then in a few days turned off. So I have not been into the dealership yet. I assume it is a 02 sensor. I have noticed the car is shifting poorly, which I would attribute the on board computer getting bad information.

 

My SES light came back on again after is was reset. I did some other internet searching. I found a thread saying that this code it is a cat going out and it needs to be replaced. I could not find which type of car the thread was about.

You know, I haven't been happy with the shifting either. It has to be related.

 

P0420 is not an O2 sensor code.
There is a TSB on this and you can fix it free if your I30 is still under warranty. It requires either (1) ECU reprogramming or (2) replacing catalytic converter (in the worst case senario). I got my local Infiniti dealer done (1) last yaer and the code hasn't come back since then.

P0420 issue is somewhat common in 5th Generation Maximas and you can find the same kind of information on this in 5th Gen. Maxima Forum.

If you go to an Infiniti dealer, do not reset the ECU.

 

Did Nissan extend the warranty for this issue? My '00 I30 has 53K miles. I wonder if it would be covered?

 

www.nissan-techinfo.com

look up the tsb for it

 

yeah!!! 53k is under warranty...go to dealer and tell them u have that code!!!

 

Thanks for the link, Larrio.

Sounds like it just needs the ECU re-programmed. Can this be done at home? Or, do I have to take it in? I see you can download ECMs from their site.


"SERVICE INFORMATION
If an applied 2000-2001 Maxima has a MIL "ON" with DTC P0420 (Three Way
Catalyst Function) stored in the ECM, it may be the result of an internal
ECM Program Misdiagnosis.

The catalyst should not be replaced. This bulletin provides updated ECM
data
to reprogram the vehicle's ECM to correct the condition."

NTB00070


IF YOU CONFIRM: An applied vehicle has the following symptoms: · MIL 'ON' with DTC P0420 stored AND · Vehicle runs OK and does NOT have a misfire or driveability incident ACTIONS: 1. Confirm this bulletin applies to the vehicle you're working on. Refer to the Repair Flow Chart on page 3 for details. 2. Compare the current ECM part number to Chart A on page 5. · If your ECM part number is listed in Chart A, reprogram the ECM to the latest ECM data. See ECM REPROGRAMMING on page 6 for details. Do NOT replace any parts in this case. · If your ECM part number is NOT listed in Chart A, you do not have to reprogram the ECM. But you will have to replace the Front Tube Assembly and the Front H02S1-B1 Oxygen Sensor. See Parts Replacement on page 10 for details. See this bulletin for further detail.

 

you have to pay to download ECMs and then you'll need the hardware (nissan consult II) to actually program that into the computer. So no, it can't be done at home

 

Here is some more useful informations regarding this issue:

Both the ECU and the catalyst system are covered by the Federal
8/80 Emissions warranty (check the warranty book that came with
your car). Many people have had Nissan pull the code and reflash
the computer for free well after the 3/36 warranty has expired.
Call up your dealer, tell them the code and that you're aware
of the TSB, and ask them if they'll cover it under the Federal
Emissions Warranty. If they won't, call Nissan USA and complain.
That should be enough. But if they try to play hardball, tell
them you're calling the EPA (800 number is in your warranty book).
BTW, that TSB only applies to California emissions vehicles, but
I believe all 2001's are California spec.

 

I don't know if the ECM reprogramming can be done at home, I doubt it though. But if as long as it's covered, why not go to an Infiniti dealer?

Infiniti's basic warranty is 4 yrs / 60,000 miles. Obviously your mileage is OK but it wouldn't hurt if you check with an Infiniti dealer to find out if your I30 is still under warrnty. All you need to do is to give them your VIN number, they can instantly tell you if it's still covered.

As for the federally mandated emissions warranty, it seems that not all the dealers are aware or honor that.

 

I have a P0420 code on a 2000 Maxima. The car runs fine except it gets 3 mpg less than before the SES light came on and stayed on. It is covered under the Federal Emissions Warranty. I am looking for Nissan's Bulletin ESM DTC P0420 to see if I can determine the problem. Can anyone help??

Thanks...

 

http://forums.maxima.org/showpost.ph...&postcount=100

http://forums.maxima.org/showthread....highlight=0420

http://forums.maxima.org/showthread....highlight=0420

http://forums.maxima.org/showthread....highlight=0420

http://forums.maxima.org/showthread....highlight=0420

http://forums.maxima.org/showthread....highlight=0420