If you still have the rattling there was a known defect with the exhaust manifolds on the 99 and later that they never really told anyone about.
There was some weld on the exhuast that after alot of miles cracked.
I was having problems with the sames codes and cleaned the sensors and it went away for awhile but I recently let the RX sit a week and started it up and finally got the weld the split and started to get noises. Lexus replaced the exhaust tried to con me into a sensor and the codes never came back.
I did some research and found that Lexus changed the design after 2000.
You might want to check for the weld split on the exhaust manifold. Lexus
does know about the problem if you specifically ask.