Bank 2 upstream O2 heater fault.
P0050 — also written POO5O, P 0050, 0050 — is the OBD-II code for ho2s heater control circuit (bank 2 sensor 1). Same code, same fix: this page covers every spelling of it.
This is your 'pre-cat' oxygen sensor on the second bank of cylinders failing to warm itself up. It’s a classic headache on V6 and V8 engines where the sensor is tucked right up against the bulkhead.
P0050 is a sensors fault code, typically costing £80–£350 to put right in a UK garage.
What P0050 actually feels like to drive
- Engine management light (EML) staring you in the face from cold start.
- Slightly heavier fuel thirst on short trips out to the shops.
- Fails the MOT on high CO levels because the sensor isn't getting up to temp.
- Engine feels a bit 'fluffy' or hesitant for the first two miles.
- No symptoms at all once the engine is hot—it's only the cold-start phase that suffers.
What causes P0050?
- Heater failure
- Wiring fault
UK vehicles that throw P0050 most often
- Audi A6 3.0 / 3.2 FSI (2005-2011) - Common on Bank 2.
- Jaguar XF 3.0 V6 Petrol (2008-2015) - Nightmare access.
- Range Rover Sport 4.2 / 4.4 Supercharged (2005-2009).
- BMW 3 Series/5 Series (E90/E60) with the N52 engine.
- Vauxhall Insignia 2.8 V6 Turbo (A28NET).
- Porsche Cayenne 3.2 / 3.6 V6 (9PA/92A).
How P0050 is fixed
- Sensor replacement
- Wiring repair
The P0050 misdiagnosis that wastes money
I see folks rushing to Euro Car Parts for a new sensor the second they see P0050, but on something like an Audi V6 or an older Range Rover, that’s often money down the drain. Half the time, the heater circuit is fine, but the fuse has popped because of a short elsewhere, or the wiring loom has chafed against the exhaust manifold heat shield. I've had lads swap sensors twice only to find a green, corroded pin in the ECU multi-plug. Always check for 12V at the heater pins before you scrap a perfectly good Bosch sensor.
What a UK garage should charge for P0050
A decent NTK or Bosch sensor will set you back £90 to £160 from a factor like GSF or Andrew Page. Don't buy the £20 eBay specials; they last a week and the heater resistance is usually wrong. Diagnostic time is usually £50-£80. Labour depends on access—on an Audi V6, you might be looking at an hour or two (£70-£150), whereas a main dealer would easily clear £400 total once they’ve added their 'premium' mark-up and VAT.
P0050 repair cost in the UK
Most P0050 repairs land between £80–£350 including parts and labour. The spread is wide because the cheap fix (a sensor, a hose, a leak) and the expensive fix (a major component) throw the same code — which is why a proper diagnosis before parts are bought saves the most money.
Bob's tip on P0050
If you're taking it to a garage, don't just ask for 'a new sensor'. Ask them to perform a 'load test' on the heater circuit wiring using a test light, not just a multimeter. A multimeter might show 12 volts, but if the wire is hanging on by a single strand, it won't carry the current needed to work. Also, if they tell you they need to remove the manifold to get to it, get a second opinion. I’ve got a drawer full of special offset 22mm sockets just for these tight spots on Jaguars and Audis that save an hour's labour if you know the knack.
Can you drive with P0050?
Drivable.
Urgency: low.