By CO sensor, i will assume you mean 02 sensors.

Here are those codes and location of that sensor is front sensor, bank1/passenger side .. 02 heater is suspect.

http://www.peachparts.com/shopforum/showthread.php?t=143573&highlight=bank

There is an Archives/Search feature here that will save a lot of time. You will find that at the top of the web page.