One problem related to o2 sensor has been reported for the 2006 Chevrolet Trailblazer. The most recently reported issues are listed below.
Within a week's several items in my instrument cluster failed - including the O2 sensor & my oil sending sensor. . . Looking at the complaints listed on this sight, I see it is a huge issue for many Trailblazer owners. Very frustrating that nothing has been done to make gm fix these problems!.