Oxygen sensor no activity detected
P0134 - upstream of catalyst (front) / rear (RH) bank
P0146 - downstream (rear) of catalyst
P0154 - upstream of catalyst (front) / front (LH) bank
P0160 - downstream of catalyst (rear) / front (LH) bank
Emissions Equipment Information
Three o2 sensor system (KL engine with one catalytic converter) - A front sensor is positioned on the LH bank and a middle sensor is positioned on the RH bank upstream of the catalyst for closed loop fuel control. A rear sensor is mounted downstream of the catalyst to monitor its efficiency.
Four o2 sensor system (KJ / KL engine with three catalytic converters) - Front sensors are mounted upstream of the RH and LH warm-up three-way catalyst (WU-TWC) for closed loop fuel control. Rear sensors are mounted downstream of the WU-TWCs to monitor their efficiency.
Diagnostic Support Notes
[P0134 / P0140 / P0146 / P0154 / P0160 - From 2002 Mazda Millenia factory service manual]