FAILED YOUR MOT? WE CAN HELP.

If your diesel vehicle has failed its MOT due to a DPF warning light, excessive smoke, or an emissions failure — don't panic. Auto Guru specialises in exactly this situation.

Our mobile DPF cleaning and diagnostic service can come directly to you, resolve the fault, and get your vehicle back on the road and ready for retest — often on the same day.

Garages & trade enquiries welcome. If you manage a fleet or run a garage and need a reliable DPF specialist to refer customers to, we'd love to hear from you. We offer trade rates and fast turnaround times to keep your customers moving.

📞 Call us today to book your post-MOT DPF clean — we'll get you sorted quickly, professionally, and at a price that makes sense.

What is an MOT test? An MOT (Ministry of Transport) test is an annual inspection required by UK law for vehicles over three years old. It checks that your vehicle meets minimum road safety and environmental standards. Failing an MOT means your vehicle cannot legally be driven on public roads until the faults are rectified.

How does an MOT affect diesel vehicles? Diesel vehicles face specific emissions checks during an MOT. Since 2018, MOT testers check for DPF tampering and measure particulate emissions. A blocked, damaged, or removed DPF is an automatic MOT failure.

Will a blocked DPF fail an MOT? Yes. A blocked DPF that causes excessive smoke or triggers a warning light will result in an MOT failure. Having your DPF professionally cleaned before your MOT is one of the most effective ways to ensure a pass.

What happens if my DPF has been removed? DPF removal is illegal in the UK for road-going vehicles and is an automatic MOT failure. MOT testers are trained to visually inspect for DPF removal and check for evidence of tampering. Driving without a DPF can also result in a fine of up to £1,000 for cars and £2,500 for vans.

What emissions checks are carried out on diesel vehicles during an MOT? The MOT includes a smoke opacity test, which measures the density of exhaust smoke. Excessive black or grey smoke indicates incomplete combustion or a DPF issue. Since May 2018, a visible DPF warning light is also an automatic failure.

Can an engine warning light cause an MOT failure? Yes. Any illuminated warning light — including the engine warning light or DPF warning light — is an automatic MOT failure. All warning lights must be off and faults resolved before presenting your vehicle for test.

How can I prepare my diesel vehicle for an MOT?

• Ensure no warning lights are illuminated
• Have your DPF inspected and cleaned if needed
• Check your exhaust for excessive smoke
• Ensure your vehicle has been driven on a motorway recently to allow passive regeneration
• Book a pre-MOT diagnostic check if in doubt

How much does an MOT cost in the UK? The maximum MOT fee set by the DVSA is £54.85 for cars. Many garages charge less. Retests may incur additional charges depending on the garage and the nature of the failure.

What is a DPF advisory on an MOT? An advisory is a note on your MOT certificate flagging a potential issue that doesn't yet constitute a failure but should be monitored or addressed. A DPF advisory typically means the filter is showing early signs of blockage or wear and should be inspected soon.

Can I drive my car if it fails its MOT? If your vehicle fails its MOT and the previous certificate has expired, you cannot legally drive it on public roads (except to a pre-booked garage for repairs). If the MOT expired during the test, you may drive it home or to a garage for repair.

How does a professional DPF clean help with MOT preparation? A professional DPF clean restores your filter to near-original flow rates, eliminates excessive smoke, and clears DPF-related fault codes — directly addressing the most common reasons diesel vehicles fail their MOT. Auto Guru recommends booking a DPF clean 2–4 weeks before your MOT date.

Does Auto Guru offer pre-MOT DPF checks? Yes. Auto Guru's mobile diagnostic and DPF cleaning service is ideal for pre-MOT preparation. We'll assess your DPF health, clear any fault codes, and ensure your vehicle is in the best possible condition before test day — all at your home or workplace.

What year did DPF checks become part of the MOT? DPF checks were introduced into the MOT in February 2014 for visual inspection, with stricter emissions and warning light checks added in May 2018. These checks continue to tighten as the UK moves toward cleaner air targets.