2008 Camry O2 Sensor
 

I am pulling a code for a Bank 1 Sensor 2 on my 2008 Toyota Camry 4cyl. The light comes and goes but I have somewhat of a rough idle. This is making me angry as it happens right at 40,000 miles and I have no warranty to fall on. Which sensor is it and which do I order, I will be replacing it myself this week. Thanks in advance.