The Nissan Path

took my 2006 Nissan pathfinder to dealer they said my catalytic converters in bank 1 and bank 2 are bad
p0420 and p0430 are the codes
we just changed the cat in bank 1 not but a year ago if that
don't wanna put new ones in again until I find cause of failure
so I bought a obd2 meter to read live data on my o2 sensors
finding something interesting
any advice on this or cause would be appreciated

o2s11 reads slow fluctuation
o2s12 reads a constant 750 no movement with a n/a for %


o2s21 reads slow fluctuation
o2s22 reads fast fluctuation with a n/a for %


any help at all would be great before I shell out major cash to fix

No one knows whats up with this huh dont sound good

i don't know about that, but i do know that cat damage can result in engine damage, which can result in cat damage................
this might be a good time to check engine compression & leakdown to be sure there isn't an underlying issue

I'm having this exact same problem with mine, they keep resetting the codes and the light keeps coming back on. Luckily my used car dealer is footing the bill as all this happened within a month of buying it. it's had numerous things done to it but they seem to be dancing around the actual problem. It's even had a bottom half engine rebuild because of an engine noise, but that didnt solve the fact my engine light keeps coming back on with these codes.

My mechanics theory is that the timing chain has jumped a tooth and he reckons that the engine is Over fueling, which would set off the o2 sensors because of emissons.

I'm sorry im not very technicly minding with cars, I wish I was! But thats what i've been told and my car is strill in the garage so I will let you know what happens with mine! Hope this is of interest to you.

If the timing was jumped a tooth, the first thing you would get is a P0011 or P0021 DTC for the variable timing (I know because I once replaced a timing chains on a VQ40DE with the primary chain a tooth off). If you are getting P0420 and/or P0430 code(s), and assuming there are no exhaust leaks, the usual problem is that the upstream catalytic converter(s) is/are no longer efficient in breaking down the exhaust gases and the converter(s) need to be replaced. Some have reported that they replaced all of the oxygen sensors on each, specific bank and the catalyst codes went away. I think that calls for speculation in that I find it unlikely that all four O2 sensors would be faulty and not one set a trouble code, but I'm only repeating what I read in a few posts.

So....
My cars been in the garage just over 2 weeks now with this problem, apparently he's taken on too muchg work and my car has only just been looked at, Here is what the mechanic has just told me...

"I have MOVED the sensors and REWIRED them."

How is that going to solve the problem? other than tricking the car into thinking there is no problem and not showing my engine light?

I'm very dubious now and don't really want to take the car back off the dealers. I bought it in January and it has spent 9 weeks in the garage. I want rid of this car now!

I think you need to get your Pathy to a new shop. It doesn't sound like he knows what he's doing!