P0145 code meaning
O2 Sensor Circuit Slow Response Bank 1 Sensor 3
Powertrain system Generic code P01xx codes Check engine light
What P0145 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. P0145 means sensor 3 reacts too slowly to mixture changes, typically measured around fuel cut-off as for sensor 2 (P0139). No manufacturer document using exactly this code was found – Jaguar Land Rover, the only documented user of sensor 3, does not list it. The description rests on CARB's response-rate requirement for downstream sensors and on the sensor 2 test logic. When it fails, the control module stops the downstream trim and cannot evaluate the converter; there is no limp mode.
P0145 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 P0145
- Check engine light on (usually after two drive cycles)
- Usually no noticeable change in driving
Common causes of P0145
- Most likelySensor aged or contaminated (oil ash, silicone, additives)
- PossibleExhaust leak ahead of the sensor
- PossibleSensor heater weak, sensor too cold
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 P0145 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. |
| 45 | The exact fault in that area. |
What to do next
- Note P0145 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 P0145
What does P0145 mean?
P0145 means "O2 Sensor Circuit Slow Response 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 P0145?
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 P0145 fail an emissions test?
Yes, it can. P0145 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 P0145 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 P0145 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.