This 2019 MINI Cooper Clubman came to us after failing its MOT due to a fault code that indicated a failed catalytic converter. The dealer quoted over £1,800 for parts and labour. But we weren’t convinced…
After performing a boroscope inspection, we found that the catalytic converter was completely fine. The real issue? A glitch in the engine control software.
For just £100, we performed a simple software update and the fault disappeared — no new parts needed!
What You’ll See in the Video
- Real-world B38 diagnostic process
- Live footage of the boroscope inspection
- Discussion of the incorrect fault code
- Software update being applied
- Result: no more fault, no CAT replacement needed
Common Symptoms of This Fault
- MOT failure due to emissions fault code
- Engine management light on
- Dealership quote for replacement CAT (B38 MINI or BMW)
Why This Happens
The B38 engine family, used in many MINI and BMW models, is prone to false catalytic converter readings caused by outdated or glitchy software. A visual inspection is essential before agreeing to expensive work. If the CAT looks fine, it probably is — and a software update could fix the issue.
FAQs
Does this fault only affect MINIs?
No — the B38 engine is also found in smaller BMWs like the 1 Series and 2 Series.
How long does the software update take?
We allow up to 90 minutes in the workshop, including diagnostics and post-update testing.
Will the fault code return?
Not if the root cause was software. If the CAT was genuinely degraded, the fault may recur.
Can you carry out this fix for me?
Yes — we offer B38 diagnostics and software updates at our West Midlands workshop.