Every now and then, we get a call from a customer who’s had work done elsewhere — but their vehicle still isn’t quite right.
This time, it was a Mercedes C200 D from Truro, which had already been to another garage for a DPF delete and EGR delete. Despite the previous work, it was still showing an engine management light (EML) and multiple diagnostic trouble codes (DTCs).
At Kernowsport, we pride ourselves on not just tuning vehicles — but diagnosing them properly.
🔧 Advanced Diagnostics and Code Correction
When the Mercedes arrived, our first step was to run a full scan using our Autel diagnostic system, which allows us to see every stored and pending fault code in the ECU.
It didn’t take long to discover that the previous garage had missed some key steps in properly coding out the DPF and EGR systems. This meant the ECU was still detecting those components as missing and triggering the check engine light.
Fortunately, with our professional-grade ECU software, we were able to:
- Identify the incorrect DTC mapping
- Correctly code out the redundant system checks
- Fully clear the engine management light (EML)
Within an hour, the Mercedes was back to running cleanly, fault-free, and performing just as it should.
If you’re having similar problems after work done elsewhere, we can help. Learn more about:
⚙️ Why Choose Kernowsport for ECU Diagnostics in Cornwall
What sets Kernowsport apart is our combination of experience and technology. We use tools from Alientech, Magic Motorsport, and Autel to provide the most accurate ECU reads and software adjustments possible.
When other garages struggle to identify lingering fault codes or incomplete remaps, we can:
- Perform deep ECU health scans
- Access manufacturer-level software systems
- Correct improper deletes or faulty maps done elsewhere
- Restore proper engine function without unnecessary parts replacement
We cover all of Cornwall, from Truro and Redruth to Penzance, Newquay, and beyond.
✅ Back on the Road with a Fault-Free Mercedes
Once the job was complete, our customer left with a fully repaired Mercedes and no dashboard warning lights. The DPF and EGR systems were now properly removed from the ECU software — the way they should have been from the start.
It’s always rewarding to help a customer who’s been let down elsewhere, and it’s a great reminder that not all remaps are created equal.
If your car has been tuned but still shows EML lights, DPF errors, or AdBlue faults, let Kernowsport take a look — we’ll get it sorted quickly and properly.
📞 Contact Kernowsport today for expert diagnostics and ECU solutions across Cornwall.
🔗 Related Kernowsport Services
At Kernowsport, we specialise in advanced ECU tuning and fault diagnostics for cars, vans, and commercial vehicles throughout Cornwall.
Explore our most popular services:
- 💨 DPF Delete & Cleaning
- 💧 AdBlue Delete & Repairs
- 🔧 EGR Delete
- ⚙️ ECU Remapping
- 💪 Performance Tuning
- 🔍 Vehicle Diagnostics
- 🚐 Mobile Tuning Service – We Come to You
If your Mercedes, Audi, VW, or any other vehicle is still showing fault codes after a remap,
📞 get in touch with Kernowsport — Cornwall’s trusted experts in DPF, EGR, and ECU correction.













