2009 XRS

I would say so. It will be under the driver/passenger front seats more than likely. Some sensors may be on top of the exhaust pipe (between the pipe and the underside of car floor) in which case you might have to remove the exhaust mid pipe which could potentially be a huge pain. Most newer vehicles have gotten better at being "mechanic friendly" though so I would think you could remove it if you just jack up the car and crawl underneath. You may want to go buy an O2 sensor socket at local parts store. There are two styles, enclosed and crow-foot style like a wrench head. The enclosed style works well as it has a slit down the side for the sensors wire to come out. The crow- foot style is useful if sensor is hard to get at with a normal rachet. Very easy to replace these so long as the exhaust isnt corroded to the point where the sensor is frozen in its threaded socket.