# DTC Code P0420 - 2005 Nissan Pathfinder SE Offroad 4.0L



## a_died_rich (Feb 22, 2016)

I will start from the beginning I got code P0345 (Camshaft Position Sensor Circuit Bank 2) ordered both the sensors and installed them. Then I got code P0420 (Catalyst System Efficiency Below Threshold Bank 1). Which I know is the passenger side. So I ordered both Catalytic Converters and both Oxygen Sensors installed them also. While waiting for the Catalytic Converters to arrive I went ahead and changed the spark plugs. And still I am getting Code P0420. I am pretty good with vehicles but this SOB is getting on my nerves. It's my wife everyday vehicle and need to get it figured out before her birthday in a few months to pass the emissions. Any help or suggestions will be greatly appreciated. Feel free to ask me any questions you have.

P.S 
The Pathfinder pretty much would turn over in a half a second BUT ever since it threw code P0345 (which I replaced both sensors) it now takes 3-4 seconds to turn over. To answer the question before it's asked no it doesn't seem to be sputtering or missing.

Thanks in advanced.

Adam


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## smj999smj (Jan 1, 2006)

If you used aftermarket cam sensors, replace them with genuine Nissan sensors. Most of the aftermarket sensors are garbage. A bad cam sensor can cause damage to the catalytic converter, which makes sense why it threw the catalytic converter code. Once again, if you used an aftermarket converter, it could be the problem. It could also be cause by a leak at the manifold to converter flange if it didn't seal properly; hopefully, you installed a new crush gasket, but that's not always a guarantee.


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## a_died_rich (Feb 22, 2016)

These are the cam sensors I installed.


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## a_died_rich (Feb 22, 2016)

Also yes on the crush seal. Actually the one that was sent with the Catalytic Converter had a dent in it. So I ran to the local part store to get a different one.


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## smj999smj (Jan 1, 2006)

The only other thing I can recommend is that you download the factory service manual for your vehicle and follow the diagnostic steps for the P0420 codes, which is the upstream converter on the right bank. You can download manuals for free here:

Nissan Spare Parts Catalog


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