C1201 P0420 P0430 Codes - 2005 V6

[FishTown]

First off, let me I'm sorry... it looks like this one has maybe been discussed quite a bit, but I couldn't find a discussion with this exact combination of codes. Also, I rarely spend any time on this forum. My wife's 4Runner has been great the past 3 years, so I have only come here to browse the classifieds every now and then. I usually hang out at ih8mud diagnosing my 1987 FJ60.

C1201 - Engine Control System Malfunction
P0420 - Catalytic System Efficiency Below Threshold Bank 1
P0430 - Catalytic System Efficiency Below Threshold Bank 2

What should I do at this point to further diagnose the problem? Run seafoam through the engine? Check the cats with temp. gun (if so, where exactly and what temp. should I expect?) Check O2 sensors (if so, how does one do that exactly?) If someone wanted to point me to a thread that has been particularly helpful, that would be appreciated as well. Diagnosing problems on a 30 year old truck is so much easier...

 

[FishTown]

Anyone?

 

[FishTown]

Last try...

 

[Supersonic]

With all three set I'd start at looking for a bad ground connection. It would seem unusual for both catalytic converters to go bad at once, but that's what I would look at next, being C1201 - Engine Control System Malfunction might just be a symptom of the other 2 codes.

Is there some catalytic converter cleaner on the market you could try? I'd look for that as opposed to removing/replacing the converter. But if you've already seen more discussion on similar problems, you probably know more than I do and I'll have to defer any more comment until I talk with a couple of others who got more experience than I.