2006 LX470 - P0430 Question

[Spacemunki289]

All - Did some homework here and believe that this is most commonly a (passenger side) a botched downstream O2 sensor rather than the catalytic converter proper.

Please note:

1. Engine sounds perfect as it always has
2. No heavy exhaust
3. No rotten eggs smell
4. No rattling in CC
5. No loss of power
6. No change in mileage

Ask on my end was for my shop to replace the downstream O2 sensor (gave it a run myself, but it's the original and damn near welded into the CC); they're coming back with the below and want to replace the full assembly. Can anyone smell test this for me and let me know if this is necessary or just the easy button? I would prefer to run the O2 replacement, wipe the light, and see how things resolve first. Vehicle has been meticulously maintained since I bought it at 192k (I know), currently 227k with zero issues following getting it up to spec and running a full baseline. Please see the below for reference, it was provided sans too much context. Thanks regardless.

 

[dbleon]

I would try replacing the up and downstream O2s in a pair before riding the cat

 

[Deflagrate]

I second that. You're around the mileage they can start to fail in my experience. They might save you from buying an expensive new cat, or you might just end up replacing something that you'd need to in the not too distant future anyways. However, I've never had a P0430. I just did both bank 1 sensors, and I had a P0138 IIRC (which said downstream, but was actually resolved by replacing the upstream).

 

[Spacemunki289]

Thanks for the above - going to change out front and rear O2 passenger side sensors and see where that takes things. Really appreciate the perspective, will let you know how things shake out.