Question 1

Can I still drive my car after it fails its MOT on emissions?

Accepted Answer

If your current MOT certificate is still valid on the day of the test failure, you can legally drive the car — but only to get it repaired or retested. If the certificate has already expired, you must not drive it on public roads until it has passed a retest.

Question 2

How much does it cost to fix an emissions MOT failure?

Accepted Answer

The cost depends entirely on the root cause. A simple fix like an oil service or replacing an oxygen sensor can cost £60–£150. A faulty catalytic converter can cost £150–£400+ for parts and labour. At MnF Motors, diagnostics start from £60 and we'll quote you before any work begins.

Question 3

Will an oil change fix an emissions MOT failure?

Accepted Answer

Sometimes, yes. Old, degraded engine oil increases hydrocarbon emissions. A fresh oil and filter change — around £60–£80 at MnF — can bring readings back within limits, especially on petrol engines that haven't been serviced recently.

Question 4

How long does an emissions repair take?

Accepted Answer

Minor fixes like an oil change or sensor replacement can be done same-day or next-day. More involved repairs such as a catalytic converter replacement typically take a few hours once parts are confirmed. MnF Motors will give you a clear timeframe after diagnosis.

Question 5

Does MnF Motors offer a free retest after an emissions repair?

Accepted Answer

If MnF Motors carries out the repair within a reasonable timeframe following an MOT failure, a partial or free retest is available. Call us on 020 8803 1231 to confirm the exact terms for your vehicle.