I am trying to figure out where to start with fixing the issue behind this P0430 code. I read that it could be plugs, o2 sensors etc etc. I have a 2011 Accord, v6 with 125k all original. It did have o-rings replaced under a recall but no other work done. So where do I start. I need to replace plugs since they are originals. Should I start there, then O2 sensor and finally cats? Any help appreciated.

 

P0430 will most likely be due to a bad cat. It is not like older cars where it can be due to the O2 sensors.

If the spark plugs need to be replaced, do so. But, it will probably need a new cat.

 

Thanks Redbull, I have heard people say to use OEM Cats but it looks like many manufacturers list their parts as OEM. How do I figure out what is actually OEM and do I in fact need to go with OEM.?

 

OEM cats are generally better quality internals, etc. than aftermarket; and should last longer.

I do not know who the Original Equipment Manufacturer is for the Honda cat for your car.

Safest way to ensure an OEM cat is to purchase from a Honda dealer. On-line Honda dealers like Bernardi Honda Parts, Majestic, etc. sell Honda parts below list price.

In your first post, you mention o-rings replaced under a recall, are you actually referring to the warranty extension due to misfire trouble codes, where they replaced affected piston rings? If so, spark plug # 1, 2, 3, & 4 may already have been replaced. See attached pdf service bulletin.

P0430 is related to Bank 2 (which is the front cat).