Powertrain, generic · Fuel and air metering

P0146 O2 Sensor Circuit No Activity Detected Bank 1 Sensor 3

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

Sensor 3 is a third oxygen sensor on bank 1, behind a second converter or converter brick. It only exists on some vehicles – documented for Jaguar Land Rover's 3.0 V6 supercharged (2013–2016, where sensor 2 is 'mid-cat' and sensor 3 'post-cat') and Ford systems that monitor part of the converter volume. P0146 means sensor 3 produces no voltage of its own and only the control module's bias voltage is seen, as for sensor 2 (P0140): GM evaluates a signal stuck in the 401–548 mV band, a high internal resistance or, with 1900 mV bias, an open circuit. No manufacturer document using exactly this code was found; Jaguar Land Rover lists only P0142–P0144 and P0147 for its sensor 3. When it fails, the control module stops the downstream trim and cannot evaluate the converter; there is no limp mode.

Likely causes

Signal or ground wire open, connector off or corroded
Sensor heater failed, sensor never becomes active
Sensor worn out (no longer produces voltage)

Symptoms

  • Check engine light on (usually after two drive cycles)
  • Usually no noticeable change in driving

Repair estimate

DifficultyEasyDIY possible
Parts and labour€50–250
Time0.2–1 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

oxygen sensor bank1 sensor3oxygen sensor wiringcatalytic converter

Related codes

P0145P0142P0147P0140P0166

References: law.cornell.edu, saabwisonline.com, gsi.ext.gm.com.