P0146 code meaning
O2 Sensor Circuit No Activity Detected Bank 1 Sensor 3
Powertrain system Generic code P01xx codes Check engine light
What P0146 means
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.
P0146 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyEasy, DIY possible
- Typical labor0.2 to 1 hours
- Clears after repairAfter a drive cycle
Symptoms of P0146
- Check engine light on (usually after two drive cycles)
- Usually no noticeable change in driving
Common causes of P0146
- Most likelySignal or ground wire open, connector off or corroded
- PossibleSensor heater failed, sensor never becomes active
- PossibleSensor worn out (no longer produces voltage)
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Oxygen sensor bank1 sensor3Oxygen sensor wiringCatalytic converter
What each part of P0146 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 1 | Area: fuel and air metering. |
| 46 | The exact fault in that area. |
What to do next
- Note P0146 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0146
What does P0146 mean?
P0146 means "O2 Sensor Circuit No Activity Detected Bank 1 Sensor 3". Sensor 3 is a third oxygen sensor on bank 1, behind a second converter or converter brick. It is a generic code, so it means the same on every make.
Is it safe to drive with P0146?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P0146 fail an emissions test?
Yes, it can. P0146 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0146 to fix?
Difficulty: easy. A typical repair takes 0.2 to 1 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0146 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.