Rear O2 on bank 2 stuck rich.
P0158 — also written PO158, P 0158, 0158 — is the OBD-II code for o2 sensor circuit high voltage (bank 2, sensor 2). Same code, same fix: this page covers every spelling of it.
This code means the post-cat oxygen sensor on the second cylinder bank is reporting a voltage that's way too high, usually because the engine thinks it's running 'rich' or there's a wiring short. It's a common headache on V6 Jaguars and older Range Rovers where the wiring looms get cooked.
P0158 is a emissions fault code, typically costing £90–£320 to put right in a UK garage.
What P0158 actually feels like to drive
- The EML (check engine light) is glowing, usually after a long motorway run.
- A slight smell of 'rotten eggs' or unburnt petrol from the exhaust on cold starts.
- Fuel economy has dropped by 3 or 4 MPG according to the trip computer.
- The car feels slightly 'heavy' or sluggish when accelerating from a roundabout.
- Fail at the MOT station on the basic emissions test (CO levels too high).
What causes P0158?
- Failed sensor
- Fuel contamination
- Short to voltage
UK vehicles that throw P0158 most often
- Jaguar XF 3.0 V6 (2008-2015) - Very common wiring chafe.
- Range Rover Sport 3.6 TDV8 (Post-cat sensors on some exports).
- Vauxhall Insignia 2.8 V6 VXR (A28NER) - High heat environments.
- BMW 3 Series 325i/330i (N52/N53 engines) - Post-cat sensor failure.
- Chrysler 300C 3.5 V6 - Oxygen sensor bung corrosion.
- Audi A6 3.2 FSI - Sensitive to sensor aging.
How P0158 is fixed
- Replace O2 sensor
- Check for injector leaks
The P0158 misdiagnosis that wastes money
I see lads constantly throwing a cheap universal lambda sensor at this one, only for the light to pop back on before they've even finished their brew. They assume the sensor is just 'tired', but on these V6 Jags and Beemers, a P0158 is often a 'liar' code caused by a leaking injector on Bank 2. If the injector is dripping fuel while you're parked up, the sensor sees a massive rich spike on startup and throws a high voltage code. Don't just swap the sensor; check your fuel trims first.
What a UK garage should charge for P0158
You’re looking at about £50 to £80 for a proper diagnostic plug-in to confirm the fault. A decent Bosch or NTK oxygen sensor will set you back between £80 and £140 depending on the lead length. Labour is usually an hour (£60–£100), but if it’s seized into the exhaust—which they usually are in Scotland due to the road salt—we might need the gas torches out, which adds time. Total bill usually lands between £190 and £320 at an indie, whereas a main dealer like Jag will easily quote you £500+.
P0158 repair cost in the UK
Most P0158 repairs land between £90–£320 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 P0158
Ask the garage to do a 'voltage sweep' test on the live data before they touch a spanner. If the voltage is stuck solid at 0.9V or higher even when they create a vacuum leak, the sensor or the wiring is toast. If it drops when they lean it out, your sensor is actually working and you've got a fueling issue instead. Also, insist they use a Bosch or NTK sensor—cheap 'white box' sensors from eBay are notorious for having the wrong resistance, which just triggers a new heater circuit code.
Can you drive with P0158?
Yes but MPG suffers.
Urgency: medium.