O2 sensors are probably the most replaced part without going bad. O2 sensors seldom fail, but there are MANY situations where the O2 sensor error code will come up and there's nothing wrong with it. I had a similar problem in an old Buick not too long ago. Error code said it wasn't even getting a signal from the O2 sensor (which was not true), but the problem was related to the EGR valve. Start chipping away at what might cause a code 17 and ignore the O2 sensor for now. Don't waste your money until you've eliminated all other possibilities.