# 2006 Pathfinder error codes PO420 & PO430



## Bossmookie (Dec 7, 2011)

Have 2 codes from OBDCOM PO420 & PO430. What do I need to do.:wtf::wtf:


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## smj999smj (Jan 1, 2006)

These are catalyst efficiency codes and usually mean that you need to replace the catalytic converter, or in this case "converters," to correct. This would be the converters between the upstream and downstream oxygen sensors and not the converters that sit after the downstream O2 sensors. I've heard of a few instances where 05-06 R51 owners have had issues with bad EGI relays in the IPDM/ER causing the converters to fail. If it hasn't been replaced, already, it probably would be a good idea to replace it along with the converters. There are a couple of other things that can cause the P0420/430 codes to set, ie exhaust system leaks. There is a diagnostic procedure in the FSM to follow to diagnose these codes, but, in my experience, 99% of the time it turns out to be bad catalytic converters.


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