Heated Oxygen Sensor No. 2

Heated Oxygen Sensor No. 2 (HO2S2) is mounted just after Warm-Up Three-Way Catalyst (WU-TWC). HO2S2 operates similar to HO2S1 and is used by PCM to monitor catalyst efficiency. HO2S2 is normal when its activity appears lazy or inactive. For component locations, see Figure or Figure .