Where is and what is there about an external “oil hose” (WTI) which can blow at 160K miles, you lose considerable oil, but is replaced without question or charge by the dealership?
These external oil lines have been known to rupture at mileages as low as 30k. I strongly suggest that you request that yours be replaced at Toyota/Lexus expense, rather than your expense. If it ruptures, you would be likely to experience catastrophic engine failure due to lack of lubrication.
This external oil line problem is a known issue with Toyota V-6 engines of recent vintage, and your Lexus ES 330 is, in reality…just a Toyota Camry in fancy dress. Of course, you do have the luxury of much better customer service for the significantly higher price that you paid for your fancied-up Camry. Hopefully that deluxe customer service will yield a free repair, even if you are past warranty.