# 2002 Pathfinder Code P0430 - Catalytic Converter?



## willy0505 (Apr 9, 2008)

Hey all - I have used this forum and saved more than a few bucks on my pathfinder. So thanks for the help to everyone that takes 15 minutes out of their busy day to respond as it translates to real dollars.

So here is my question - I have been able to do a pretty quick search on this forum and find the answer to most of my questions, but now I am faced with a pathfinder that is due for inspection (April of 2013 no less) with a check engine light that has been on for about 3 weeks. 

So I took it to Autozone today and got the P0430 code. Its description says:

Catalyst system efficiency below threshold - bank 2

Probable causes:
1. Large vacuum leak
2. Fuel system fault
3. Ignition system fault
4. Failed bank 2 catalytic converter

My questions are - what the heck does #1 even mean & is #2 really even worth trying (i.e. do I just inject fuel system cleaner to try that)?

As for #3 - I did replace my starter about 45 days ago and the light came on about 25 days ago although I dont think these are related (but there are true experts on this forum!).

So I guess that brings me to the real question - is my problem most likely #4 and it needs to be replaced & if so, is this something that I can do myself (I can do enough to be dangerous - -i.e. change starter, alternator, change the oil, etc.) - I cannot really find good instructions on this forum.

If anyone has thoughts on the solution (most common solution for this code) and any instructions on how to correct - I am really good at following directions.

Thanks in advance for the help.

W


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## BradY (Apr 5, 2013)

The catalytic converter is getting plugged. Look at Scotty Kilmer videos on youtube. He shows how to wash it out with laundry detergent or use solvent in your tank. There are videos on how to test if it is plugged. There are other Pathfinder forums that say to use 'nonfoulers' on the O2 sensors.


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## supraholic (Nov 21, 2005)

did you get your O2 sensors replaced recently?


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## willy0505 (Apr 9, 2008)

No - I did replace one of them about 3 years ago 

Also - I looked at detergent video - I am skeptical that washing would work - has anyone tried that?

I am thinking of unplugging the battery all night, filling up with some of the engine cleaner - or should I just try and replace the cat??

Thanks for looking / advice guys - I know we all have day jobs besides working on cars and reading forums!!


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## smj999smj (Jan 1, 2006)

P0420/430 codes do not mean the converter is getting clogged; it means they are inefficient at breaking down the exhaust gases. The ECM determines this by comparing the frequency of the rich to lean cycles of the front O2 sensor to those of the rear sensor, which should be approximately a 2:1 ratio, respectively. If the converter is inefficient, that ratio will be closer to 1:1 ratio. There are several things that can cause the P0430 code, but probably 95% of the time or better, it's the catalytic converter. Bank #2 would be the converter on the left, or driver's side of the vehicle, which sits between the front and rear O2 sensors. If an engine is running too lean, or too rich, or misfiring, or if there are exhaust leaks near the O2 sensors, they can effect the O2 sensor readings and cause the P0420/430 codes to set. A bad O2 sensor can also do this, but will usually set an O2 sensor trouble code in the process. If you download a factory service manual, it will give you the diagnostic flowchart for the P0430 DTC. This list the steps to properly isolate the cause of the problem that is triggering the code. As far as your ability to diagnose or to change the converter, only you can answer that. How hard the job is also depends on how cooperative the bolts are at coming out and/or how rusted they are. It's also not a fun job to do on the ground, if you don't have access to a lift...but it is doable.


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## supraholic (Nov 21, 2005)

Same code showed up on mine (2001 model) just after an O2 sensor (downstream of cat) replacement. I had the dealership update all the firmware updates to the ECU, and the light was gone..your case, its been 3 years since O2 sensor replacement..


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