NOx Sensor Repair
Mobile across Birmingham & the West Midlands
A failed NOx sensor is the single most common AdBlue fault — and the usual cause of an AdBlue warning, limp mode or a no-restart countdown. We come to you, diagnose whether it’s the upstream or downstream sensor, fit the correct replacement, code it to your vehicle and clear the faults. Road-legal, MOT-ready, and done on your driveway.
What does a NOx sensor do — and why do they fail?
NOx sensors measure nitrogen oxides in the exhaust so the ECU can dose exactly the right amount of AdBlue. There’s usually one before and one after the SCR catalyst. They run in fierce heat and fail regularly on higher-mileage diesels — triggering an AdBlue warning, reduced power or limp mode, a no-restart countdown and codes like P2BAF, P13DF and P20EE. We diagnose which sensor has failed, fit the correct part, code it to your vehicle and clear every related fault.
Diagnose, replace, code & clear
We confirm the failed sensor, fit the correct upstream or downstream NOx sensor for your vehicle, code it to the ECU where needed, and clear all related faults.
Road-legal and MOT-ready when we leave.
Cars, vans & light commercials
Mercedes, Ford, VW, Audi, Peugeot, Citroën, Vauxhall, BMW, Land Rover and more. If a NOx sensor keeps failing, we’ll tell you why before you spend again.
How the repair works
A clean, mobile process — we come to you.
- Confirm the fault. We scan the ECU and live NOx data to confirm which sensor has failed and rule out related issues.
- We come to you. Our specialist arrives at your home, work or yard anywhere across Birmingham & the West Midlands.
- Fit the correct sensor. We replace the upstream or downstream NOx sensor with the right part and code it to your vehicle where required.
- Clear & confirm. All related fault codes are cleared and we confirm the warning is gone and the system is healthy before we leave.
Symptoms of a failing NOx sensor
If you recognise these, a NOx sensor is the likely cause.
AdBlue warning light
An AdBlue or engine management warning that won’t clear is the classic sign.
No-restart countdown
Messages like “no restart in 1000km” as the system protects itself.
Limp mode / lost power
Reduced power and performance as the ECU restricts the engine.
Poor fuel economy
Incorrect dosing pushes fuel consumption up.
Recurring fault codes
Codes such as P2BAF, P13DF and P20EE that keep returning.
Failed emissions / MOT risk
A faulty SCR system can mean an MOT failure on emissions.
NOx sensor — repair or keeps failing?
We fix the cause, not just the symptom.
One-off failure
Most NOx sensors simply wear out — a correct replacement and code clears it for good.
Recurring failures
If a sensor keeps failing, there’s usually an underlying cause — we diagnose it before you spend again.
Persistent faults
Where a fault keeps returning, a permanent software solution can resolve it for good.
Areas we cover — Birmingham & the West Midlands
We’re a Birmingham-based mobile AdBlue specialist, fully mobile across Birmingham and the wider West Midlands — we come to you, wherever you are.
Birmingham
Birmingham city centre, Erdington, Kings Heath, Selly Oak, Edgbaston, Harborne, Solihull and Sutton Coldfield.
Black Country & Coventry
Wolverhampton, Dudley, Walsall, Stourbridge, Halesowen, Coventry and Bilston.
Wider area & beyond
Cannock, Telford, Tamworth, Lichfield and Staffordshire — and further afield by arrangement.
Why choose Repair My AdBlue
Practical reasons West Midlands drivers choose us for NOx sensor work.
Fully mobile
We come to your home, work or yard 7 days a week — no garage visit, no trailering a vehicle in limp mode.
Diagnose, don’t guess
Every job starts with a full ECU scan so we fix the real cause — not just clear a code that comes straight back.
Honest advice & a quote first
We’re straight about what’s road-legal and what’s off-road only, and we quote before any work begins.
Related services
NOx sensor faults often sit alongside these.
NOx sensor repair — common questions
Quick answers before you book.
What are the symptoms of a failing NOx sensor?
An AdBlue or engine warning light, a no-restart countdown, limp mode or lost power, poorer fuel economy, and recurring codes like P2BAF or P13DF. A quick scan confirms it.
Can a NOx sensor be cleaned, or does it need replacing?
NOx sensors are sealed electronic units — once they’ve failed they need replacing, not cleaning. We fit the correct part and code it to your vehicle.
How much does NOx sensor replacement cost?
It depends on the vehicle and whether it’s the upstream or downstream sensor, so we quote before any work. Tell us your make, model and year for a price.
Which makes do you work on?
Mercedes, Ford, VW, Audi, Peugeot, Citroën, Vauxhall, BMW, Land Rover and more — cars, vans and light commercials.
My NOx sensor keeps failing — why?
Repeated failures usually point to an underlying issue such as crystallisation, a dosing fault or AdBlue quality. We diagnose the cause so you’re not replacing sensors over and over.
Which areas do you cover?
We’re fully mobile across Birmingham & the West Midlands — Birmingham, Coventry, Wolverhampton, Dudley, Walsall, Solihull, West Bromwich, Sutton Coldfield, Cannock and the surrounding areas, and further afield by arrangement.
AdBlue warning or countdown? Likely a NOx sensor
Tell us your make, model and the warning you’re seeing. We’ll confirm the failed sensor, fit the correct part on your driveway and clear the fault — mobile across Birmingham & the West Midlands.
Mobile across Birmingham & the West Midlands · 7 days a week · 07312 051114 · info@repairmyadblue.co.uk