AdBlue warnings, NOx sensors and EGR valves on Land Rover diesels

Which cars and engines are affected?

Land Rover and Range Rover diesels with these emissions systems:

• AdBlue (SCR). Selective catalytic reduction adds AdBlue to the exhaust to cut nitrogen oxides (NOx). NOx sensors in the exhaust tell the system how well it is working.
• Exhaust gas recirculation (EGR). An EGR valve returns some exhaust gas to the engine’s intake, and an EGR cooler, cooled by engine coolant, lowers its temperature first.

Which engines have which system varies by model and year. If you are not sure, put the registration in the enquiry form and we will check. For other work on these cars, see our Land Rover and Range Rover specialist page.

What are the symptoms?

AdBlue and NOx faults:

• an AdBlue warning on the dashboard
• a countdown of the distance left before the engine will not restart

EGR faults:

• the engine management light
• low power
• limp-home mode, where the car runs with reduced power

Do not ignore an AdBlue countdown. When you book, tell us the message on the dashboard, the distance left and when it first appeared.

What causes it?

A warning tells you the system has detected a problem, not which part has failed. On the AdBlue side, the fault can lie in the dosing of the fluid, in a NOx sensor or in the AdBlue itself. On the EGR side, it can lie in the valve or in the cooler.

Because several faults can bring up the same warning, the dashboard message alone does not tell you which part to replace. We find out by testing, not by guessing.

How do you confirm the fault before fitting parts?

A fault code is not a repair, and a new NOx sensor will not fix a dosing fault. Before we quote for parts, we:

• read the fault memory with our diagnostic equipment
• run a dosing test on the AdBlue system
• check that the NOx sensor readings are plausible
• check the quality of the AdBlue in the tank
• compare what the engine commands the EGR valve to do with what it actually does, using live data
• smoke-test or pressure-test the EGR cooler

Our DPF and emissions health check covers these tests with a written report. We then show you what we found and send a written price. No part is fitted until you give your written approval.

What does the repair involve?

• AdBlue and NOx. We replace the part the tests prove faulty, using the correct part for your car, then carry out the adaptations the system needs.
• EGR. Depending on what the tests show, the EGR valve or cooler is cleaned or replaced.

AdBlue and SCR repairs, NOx sensor work and EGR valve and cooler work are done in-house. Once the work is done, we check that the warning has cleared and verify the repair, including a road test where appropriate. We repair AdBlue, EGR and other emissions systems; we never remove or disable them.

Can the AdBlue or EGR system be removed or switched off?

Not by us. In the MOT, emissions equipment that is missing, obviously modified or obviously defective is a Major defect. So is an engine warning lamp that shows a fault on a diesel first used from 1 July 2008.

The Department for Transport consulted in 2026 on tighter rules against emissions tampering, naming AdBlue deletion and EGR manipulation alongside DPF removal.

Do you repair Jaguar AdBlue and EGR systems too?

Yes. We carry out the same tests on Jaguar diesels, including dosing and NOx sensor tests, an AdBlue quality check and EGR valve and cooler tests, and replace only the part the tests prove faulty. The registration tells us which emissions systems your Jaguar has, so put it in the enquiry form and we will check. For other Jaguar work, see our Jaguar specialist page.

How long does an AdBlue or EGR repair take?

It depends on what the tests find, on which part has failed, and some parts may need ordering.

Before any work starts, you get a written price and a promised time for your next update. If the car needs to stay with us, ask about a courtesy car when you book.

Is there a recall for the AdBlue or EGR system?

Whether a recall applies depends on the individual car, so check your registration on gov.uk. Recall work is done by Land Rover’s network, not by us.