Modern BS6 petrol cars monitor fuelling and emissions through a network of sensors and electronic controls. A CNG system intended for such a vehicle must work with that strategy, which is why OBD-aware control and vehicle-specific calibration are important considerations.
This guide explains product and selection principles. It does not confirm compatibility, replace model-specific documents or provide a repair procedure.
What OBD compatibility means
On-board diagnostics monitors signals and corrections used by the vehicle's engine-management system. An OBD-compatible CNG controller can use relevant diagnostic information to support gas-fuelling adjustments when correctly integrated.
The presence of an OBD connector alone does not prove that a kit is suitable for every BS6 car. Software, wiring and calibration must match the application.
Mixture control and warning lights
Accurate mixture control helps the engine operate within its intended range on CNG. Poor calibration can contribute to drivability problems, excessive fuel corrections or a malfunction indicator lamp.
Diagnostic codes should be investigated, not simply cleared. They may point to fitment, calibration or an unrelated vehicle fault.
Compatibility is vehicle-specific
BS6 covers many engine and injection designs, including port injection and direct injection. Their hardware and control requirements differ, so a kit suitable for one engine may not suit another.
Confirm the exact engine code, model year and emissions configuration before selecting components.
Installation and validation
A competent installer should inspect the petrol system first, fit components carefully and calibrate the gas system under representative conditions. Post-installation scans and road checks help verify changeover, fuel correction and drivability.
Owners should retain the configuration and service records for future diagnosis and maintenance.