Can You Still Pass an MOT After AdBlue or Other Emissions Deletes?
I Fix AdBlue | November 2025
Introduction
If you’re fed up with AdBlue faults, limp mode and “0 miles until no start” messages, you’ve probably looked into AdBlue delete, DPF delete or other emissions deletes. One of the first questions drivers ask is: “Will my van still pass its MOT?”
In this guide we’ll cover:
- How MOT testers currently check emissions systems
- What happens if AdBlue, DPF or EGR have been removed or disabled
- The difference between visual checks and emissions readings
- Real‑world risks and what could change in future
For a deeper legal overview beyond just MOT, see our article AdBlue delete legal UK.
What the MOT Test Actually Checks
In the UK, the MOT test for modern diesels focuses on:
- A visual inspection of key emissions components (DPF, catalytic converter, etc.)
- A smoke opacity test on the exhaust
- Dashboard warning lights – the engine management light must not be on
At the moment, most MOT stations:
- Do not plug into the AdBlue system directly
- Do not read AdBlue fault codes as part of the MOT
- Rely mainly on what they can see and the smoke test result
That’s why some vehicles with emissions deletes still pass MOT – but it doesn’t mean there are no risks. We talk more about those in why some drivers choose an AdBlue delete and what you should know .
AdBlue Delete and MOT – How It Usually Plays Out
A correctly carried out AdBlue delete will:
- Stop AdBlue‑related warning lights and countdowns
- Prevent AdBlue faults from triggering limp mode
- Keep the engine management light off (assuming no other faults)
Because the AdBlue system is software‑controlled and usually hidden under the van, there is often no obvious visual sign that the system has been disabled. As long as:
- The engine management light is off
- The exhaust passes the smoke test
- There are no obvious signs of tampering
many vehicles with AdBlue delete currently pass MOT without issue.
However, this is not a guarantee, and rules or testing technology can change. Our article can you still pass an MOT after emissions deletes? goes into more detail on this point.
What About DPF Delete?
DPF delete is treated more strictly than AdBlue delete during MOT because the DPF is:
- Physically visible in most exhaust systems
- Specifically mentioned in MOT guidance
If the tester can see that the DPF has been removed or obviously tampered with, the vehicle should fail the MOT. However:
- Some DPFs are hollowed out rather than removed
- Externally, they still look like a normal DPF can
In those cases, the MOT result usually depends on:
- Whether the tester notices any signs of modification
- Whether the vehicle passes the smoke test
You can read more about the pros, cons and risks in our DPF delete service overview.
EGR and Other Emissions Deletes
EGR (exhaust gas recirculation) systems are another common source of problems on modern diesels. Many owners choose EGR delete to improve reliability and reduce soot build‑up.
From an MOT point of view:
- There is no specific “EGR present” visual check
- The main concern is that the engine management light is off
- The vehicle must still pass the smoke test
As with AdBlue and DPF, the risk is less about the MOT tester spotting the modification and more about how future rules or roadside checks might change.
Current Real‑World Picture (Not a Guarantee)
In day‑to‑day UK testing right now, we regularly see that:
- Vehicles with AdBlue delete often pass MOT, provided there are no warning lights and the smoke test is OK
- Vehicles with carefully done DPF delete sometimes pass, especially when the DPF can looks original and smoke is low
- Most MOT stations do not have the tools or time to dig deeply into emissions software
But it’s important to understand:
- This could change if MOT rules tighten or new equipment is introduced
- Roadside checks by enforcement agencies can be stricter than MOT
- There is always a risk when modifying emissions systems
For that reason, we always recommend reading AdBlue delete legal UK in full before making a decision.
Insurance, Warranty and Resale Considerations
Beyond the MOT, emissions deletes can also affect:
- Manufacturer warranty – most OEMs will not honour engine/emissions warranty after deletes
- Insurance – undeclared modifications can cause issues if there’s a claim
- Resale value – some buyers prefer standard vehicles, others actively want deletes
Many high‑mileage trade and fleet owners still choose deletes because the reliability and cost savings outweigh those downsides for them. Our guide AdBlue delete vs repair – what’s right for your van? walks through that decision in more detail.
Typical UK Cost Ranges (Guide Only)
To put things into context, here are general UK market ranges for common emissions‑related work. These are not specific prices for any one garage or provider.
- AdBlue system repairs (sensors, pumps, heaters): from around £300 up to £1,200+
- DPF replacement on many vans: often £700–£1,500
- Combined AdBlue + DPF work after long‑term issues: easily £1,500–£2,500+
You can see a much more detailed breakdown in our complete AdBlue repair cost guide .
Why Some Drivers Still Choose Emissions Deletes
Despite the risks, many drivers – especially those running older, high‑mileage work vans – still choose deletes because:
- They’ve already spent heavily on repeated AdBlue or DPF repairs
- The vehicle is out of warranty and mainly used for business
- They need to avoid limp mode and countdowns during working hours
We talk through these real‑world decisions in why some drivers choose an AdBlue delete and what you should know .
Related Guides
- AdBlue delete legal UK – full legal overview
- AdBlue delete vs repair – what’s right for your van?
- Can you still pass an MOT after emissions deletes?
- Why some drivers choose an AdBlue delete and what you should know
- AdBlue delete service overview
Need Help Deciding What to Do Next?
If you’re weighing up whether to keep repairing the AdBlue/DPF system or look at delete options, the best starting point is a proper diagnostic and an honest discussion about how you use the vehicle, mileage, and budget.
We offer mobile diagnostics and emissions solutions across Leicester and the surrounding areas. You can get in touch via the contact us page, or read more about our AdBlue delete and DPF delete services.
