The bank one oxygen sensor in a 2006 Chevy TrailBlazer is situated in the ventilation system simply above where joins the exhaust pipe. The oxygen sensor screens the fumes gas leaving be in to decide how much unburned oxygen is in it. At the point when the air fuELRatio is too rich this implies that the oxygen levels in the exhaust gases are excessively high. The PC will see this data and naturally will change the air fuel blend going into the choke body. To eliminate the oxygen sensor,detach the electrical connector on the end and use A7/8-inch or 22-millimeter attachment and turn it counterclockwise. It's smart to run the motor until it is at full working temperature prior to attempting to eliminate the sensor. This will cause the ventilation system to enlarge somewhat because of intensity making it simpler to eliminate the sensor.