Bentley – Dezaktywacja monitoringu katalizatora (Bosch MG1CS008)

Bentley – Deactivation of catalytic converter monitoring (Bosch MG1CS008)

November 5, 2025

In our workshop, we performed an advanced software modification of the Bosch MG1CS008 control unit in a Bentley after changing the exhaust system.
The aim of the implementation was to deactivate the catalytic converter efficiency monitoring (so-called Catalyst Efficiency Check / P0420 – P0430) , which generated errors after the installation of sports downpipes and a straight-through exhaust system.

Description of the vehicle and control unit

Make/Model: Bentley (Continental V8/W12 line – details undisclosed)
Engine: Turbo petrol (Twin-Turbo V8)
ECU: Bosch MG1CS008

Bosch MG1CS008

3SA906014A

0P2907309A

052432

0228

Original file available!

Emission control system: 2 lambda sensors per bank, active monitoring of catalytic converter efficiency
Initial condition: P0420 / P0430 errors after installing sports catalytic converters

Modification process - deactivation of catalyst monitoring

In modern VAG / Bentley units based on the MG1CS008 controller, exhaust emission control is multi-layered.
After modifying the exhaust system (downpipe, sports catalytic converter or straight pipe), the factory ECU software recognizes the lower efficiency of the catalytic converter and generates MIL errors.

The reprogramming process included:

full reading of Bosch MG1CS008 ECU in Bench mode (for security reasons),
analysis of diagnostic sections (OBD readiness monitoring, lambda efficiency, cat heating),
programmatic deactivation of the catalyst monitoring function ,
maintaining other diagnostic functions (probe monitoring, mixtures, misfires, adaptations).

The modification does not affect the fuel-air mixture or real-time control of the lambda sensors - it only concerns the catalytic converter conversion efficiency test as part of the OBD2 cycle.

Result of implementation

Controller: Bosch MG1CS008
Scope of changes: deactivation of catalyst monitoring (P0420 / P0430 off)
Probe operating mode: preserved
OBD functions: full (except catalytic converter test)
Effect: no MIL errors after exhaust modification, stable ECU operation
Completion time: ~40 minutes (Bench mode)
Control measurement: no effect on AFR / LTFT / STFT

Why tuners and workshops entrust us with ECU modifications MG1CS008

🔧 Full support for Bosch MG1CS002 / MG1CS008 / MD1CS004 controllers
⚙️ Solutions for VAG, Bentley, Audi, Lamborghini, Porsche
⏱️ Completion in 30–40 minutes
🧠 Studies based on our own definitions and experience in OEM tuning
🧩 Possibility to combine modifications with Stage 1 / Stage 2 / OPF OFF / GPF OFF / VMAX OFF

Our solutions are designed for workshops and tuners who need reliable, tested files to work with MG1 engines.

FAQ – frequently asked questions

Does deactivating catalytic converter monitoring affect exhaust emissions?
No – the modification does not physically remove the catalytic converter, but only deactivates the test for its effectiveness, which often generates false errors after replacing the exhaust.

Is lambda control still working?
Yes – all mixture control, lambda control and STFT/LTFT correction functions remain active.

Is the file available for tuners?
Yes – the Catalyst Efficiency Monitor deactivation file for MG1CS008 is available in the B2B panel for workshops.

Can this be combined with Stage 2 tuning?
Of course – monitoring deactivation is often performed in parallel with Stage 2 after modifying the downpipes or exhaust system.

Summary

✅ Bentley (Bosch MG1CS008) – deactivation of catalytic converter monitoring
✅ No MIL errors after exhaust system modification
✅ All other diagnostic functions retained
✅ File developed and ready in 30 minutes
✅ Solution for tuners and premium workshops