Fixed. Bought an "Anchor" (Made in china) from Advance for $50. The problem ended up not being the rubber mount itself. There are two allen type bolts that hold the rubber mount onto the metal bracket, they were gone. Luckily the new one came with some, and we put them on with thread lock. Big difference, less steering wheel vibration at stops. Also cleared the P0420 code, hasn't come back on yet. Gonna see what happens but so far so good.