There are several threads on MUD regarding the O2 sensors and their (perported?) affect on performance. My experience with pre-hard-failure-replacement was positive (mileage up a bit, power up a bit, sleep quality much improved).
I finally gave up on my exhaust tip and took a sawzall to it.
Hants (KD0CXL) 97 LX450 Slee Armor, 285 BFG/AT, OME 2.5", Altitude Compensator, Kimberley Kamper
"that guy down in Colorado Springs" - Jeff
"Damn you, Hants White!" - CruiserDan
"Wanna race?" - Bill Morgan
"Live long, love lots, cruise often." - Robert Fortune