take the cat all the way off the car. remove that little blue plug where the o2 sensor wires go up into the car and there is a plug up there. when the cat is off the car you'll need an open ended 22mm wrench to get the o2 sensor out.
Honda and the Honda marquee are registered trademarks of the American Honda Motor Company, Inc. Neither American Honda Motor Company nor its subsidiaries or affiliates shall bear any responsibility for Honda-Tech.com content, comments, or advertising. Honda-Tech.com is not affiliated with American Honda Motor Company in any way. American Honda Motor Company does not sponsor, support, or endorse Honda-Tech.com in any way.
Copyright/trademark/sales mark infringements are not intended or implied.