Hal,
AutoZone gave me the error code this morning: P0420 - which is for the O2 sensor. I'm assuming it will cost me roughly $400 to fix, but that's better than the alternative - replacing the catalytic converter.
-julie
Same thing happened yesterday in my 2004 RX330. I'm stopping by AutoZone today to get codes, but please continue to post your findings up here, as I'll continue to check back. Thanks, Hal.
-julie