Someone here reported that their 2017 RX 450h had the new revised exhaust. Mine is a 2017 built 11/17 and it doesn't have it. However, the 450h doesn't appear to have a problem so maybe Lexus was testing a wide sample of RX models leaving the production line. Who knows? You can easily see whether the revision has been done by looking for the round black damper as the RX is high enough to look underneath at the exhaust. Read these posts starting "here" to see what the revision looks like and much more information.

 

my 17 rx450 has it built late 11/17(28th or so of november)