P0420 and Timing Cover Leak --- Related?

After fixing the leaking gaskets after the cats, changing plugs, cleaning MAP/TB, swapping O2 sensor banks, looked for vacuum/exhaust leaks, I've determined the bank 1 cat is shot.

On closer inspection I noticed an old but slow oil leak around the timing cover where the power steering pump is mounted. This has spread rearward along the cylinder head to the front of the exhaust manifold.

I'm now wondering if oil penetrated the manifold gasket and got into the exhaust gasses.
I'm sure the material in the cats wouldn't react well in that circumstance.

Kinda makes sense due to the p0420 code being much more common than the P0430.

Anyone experienced this leak leading to a catalytic converter failure?

 

It would have to be a pretty serious leak to go all that way into the exhaust.
Our cats are only designed to make it to the end of warranty.
My right side cat went just past the warranty date so I replaced it with a Dorman unit and all has been well.
I took the OEM convertor to a local scrap guy and he looked up the numbers on the cat and it fell under a category called "low grade foreign" $40 is $40

 

You know, mileage varies wildly with regards to how long these things last. Some people on here have 300k+ on the factory cats.
I guess if you're running cruddy gas and adding questionable fuel treatments all the time your results may be lesser.

I have ideal fuel trims, A/F ratio, great milage & performance.
Not sure what else could have contributed to the bank 1 cat failing.
That oil leak is my suspicion.

Odd that your "factory" cat had a low grade rating.
Or he just told you that to drop his payout.
But $40 is $40...