P0142 O2 Sensor Circuit Bank 1 Sensor 3

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. P0142 is the general circuit code of this sensor. Jaguar Land Rover lists it with P0143, P0144 and P0147 for the post-cat sensor and names software (fixed by reconfiguring the engine module) and water-induced thermal shock as causes. No published thresholds exist for sensor 3; the logic follows the sensor 2 checks (P0136). When it fails, the control module stops the downstream trim and cannot evaluate the converter; there is no limp mode.

Likely causes

Symptoms

• Check engine light on (usually after two drive cycles)
• Catalyst monitor readiness not set
• Usually no noticeable change in driving

Repair estimate

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

Parts involved

Related codes

References: law.cornell.edu, static.nhtsa.gov, static.nhtsa.gov, newtonnet.co.uk.