# Code p0430:change one or both OS sensors



## Nwpath (May 13, 2010)

My 05 pathfinder with 95k has the dreaded p0430 code. still runs ok. I changed the after cat Ox sensor hoping it would fix the problem,but unfortunately,no joy.

Should I replace the front one also?

Anyone replace the front one and the code disaapered?


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## RedAlert (Jun 19, 2009)

Try replacing the catalytic coveter. It's big$, but will solve your problems


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## Nwpath (May 13, 2010)

that what I am trying to avoid.


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## ntech (Apr 13, 2010)

you need a kitty! done quite a few now on some high mileage 05 and 06 4.0L. Beware....the other side is probably not too far behind
save your money and dont buy any more O2's


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## Nwpath (May 13, 2010)

ntech said:


> you need a kitty! done quite a few now on some high mileage 05 and 06 4.0L. Beware....the other side is probably not too far behind
> save your money and dont buy any more O2's


no money my friend. unemployment is a terrible thing.


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## calinsantiago (Jun 29, 2011)

*Same problem*

P0420 last month and weeks later P0430 planing in replace both front catalytic, starting to believe a factory defective be the cause... come on just 100,000 and need to be replace.....


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## body80 (Mar 7, 2004)

Nwpath said:


> no money my friend. unemployment is a terrible thing.


Here you go.... It got rid of my code.
Disclaimer:
This is bad for the environment........ Do what nissan says and replaced Both Catalytic converter to the tune of over $2000...
Oh and if you break anything doing this cheaper fix it's not my fault. What worked for me may not work for you.

P420??? P430??????????????
Catalyst system efficiency below threshhold Bank 1 or 2...............right????????????????????

I have a crazy fix for this code but first alittle background. 

I started throwing P430 which is the same code as you but for Bank 2 side. I played with it for months resetting the code and paying attention to when it would come back on. I can watch the O2 sensors with my scan tool and could tell from the freeze frame of the code it was only tripping the code because the efficiency was just barely out of tolerance every now and then. (HELL IT COULD BE BECAUSE OF THE 10% ETHANOL CRAP IN THE FUEL NOW!) Now sometimes I can drive a month and sometimes only a few days before the light would come on. Which basically means my Catalytic converters were only bad from an environment stand point and just barely. There's not anything really wrong with the pathfinder. 

N-E-ways.... The BIG dollar fix is to replace back Catalytic converters which would cost quite a bit. Or trick the ECU into thinking that everything was just fine. 
I choice the cheaper route. Only cost my $10 LOLOLOLOLOLOLOLOL

Here's what you need.









Buy a package of non foulers, Start small and slowly enlarge the hole all the way up to a 1/2" drill bit. 

Now pull the rear O2 sensors and install the non-fouler onto the O2 sensor and then screw it back into the exhaust. I did it to both sides so they are the same. Everything only took my about 30 minutes. 









Now the theory behind it is the O2 sensor is now pulled out of the direct stream of exhaust gases. Because of this it's seeing less of a sample of exhaust gases. Rear O2 sensors are not used to adjust air/fuel ratios. It's there for government emissions measuring. Now that it's seeing less of the bad stuff it's sending that signal to the ECU and the ECU likes it. 

So far I've driven 8000 miles with this fix and haven't had a single problem and there's been NO LIGHT ON.
Fuel mileage didn't change AT ALL.

It worked for me!


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## G8rDuc (May 11, 2009)

Excellent fix....


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## G8rDuc (May 11, 2009)

Side note, you can get the cats on eBay for cheap...$120 per side...


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## curvecrazy (Feb 17, 2012)

*I had P0174 fixed front sensor but 5-600 miles now P0430*

As stated. 05 Pathy. 97K miles. Threw a 174 code lean bank 2. I decided to fix myself since I have the CD manual. Which was a mistake. I should have just payed the $100 to the dealer. So it took awhile as I ran through a Lucas fuel treatment. CEL stayed. I then checked for intake vacuum leaks. Cleaned my MAF sensor. Checked all my wiring. Round and round. Ultimately it seems to have been a lazy bank 2 front air/fuel sender. So I replaced that and erased the light. The light then came back and I was frustrated. Checked it again and its a P0430 bank 2 catalytic efficiency below threshold code. So I thought it might clear itself but it has not so far after several hundred miles. I did end up driving probably 5-600 miles while trying to figure out the P0174 code. Since the sensor was giving the ECM the wrong information, the ECM was adjusting the fueling as much as it could to compensate for the lean signal it was getting. Which was a false lean condition(not actually lean... just fooled into thinking it was lean. So it ran rich. I did unplug the battery negative on various occasions trying to get the base setting for my drive to work.. thinking it was actually lean when it was actually rich. I knew the truth when I pulled the front air/fuel sensor and it was brown. So that indicates physical rich. I had not worried I was damaging my converter/s cause it was telling me lean condition. 

So here I am. The question is, will this condition clear up itself with more mileage? Or will I need a new converter? If I get a new converter, will an aftermarket such as thems listed on partsgeek serve the purpose or are those inferior quality? Maybe a fix such as that listed above would do me? I really am not that concerned as long as I can get it by emissions testing in 8 months or so. 

I plan to replace the bank 1 air fuel sensor on general principle. My gas mileage had dropped off quite a lot which was aggravating. Now with one new sensor it seems to be improving. I did not previously realize that air/fuel and O2 sensors were wear items. Seems with these newer OBDII vehicles that in order to keep them meeting the requirements long term that you would have to replace the sensors on a regular basis. The manual says nothing about this. Of course, if you see your mileage drop off significant then probably a good sign somethings amiss. So possibly a MAF sensor or air/fuel sensors. 

And newer air fuel sensors would probably keep your cats in good health too me thinks. It seems to me it ain't like the old days where you had mechanical sets on your fueling and it just stayed that way and you drive on. These new POS vehicles have sensors on sensors and one reading off will cause the ECM to adjust which can then cause expensive failures to things like the cat. converters. I have read about the fix listed above before, to get the O2 sensor recessed from the exhaust stream. And I have read about siliconing (yes.. silicone?? that will foul your converter and sensors for sure right???) the rearward O2 sensor to fool it into thinking the O2 output it right. Not sure if that would work on these nissans. 

Any ideas or experiences would be appreciated. 

Also, anyone have recommendations for a reasonably priced OBDII code reader? I am thinking Actron 9580 maybe. 

Thanks..


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