BENTLEY CONTINENTAL GT GTC 18-24 3S 3SD W12 CAT catalytic converter kit

Genuine Bentley Continental GT / GTC W12 Catalytic Converter Kit

Series: 3S / 3SD (Third Generation: 2018–2024+)

For the 6.0L W12 Twin-Turbo engine in the latest Continental GT and GTC, the catalytic converter system is divided into Primary (downpipe-mounted) and Secondary (intermediate) units. Like the V8, the W12 in the 3S chassis utilizes a sophisticated emissions setup that is often shared in part with the Porsche Panamera Turbo platform.

Primary Catalytic Converters (Upper/Downpipe)

These units are bolted directly to the turbochargers. They are the most critical for emissions and are heavily heat-shielded.

• Revision Notes: You may also see suffixes like E (e.g., 971131703E) or AC depending on the specific model year and whether the car is built to Euro 6d or North American EPA standards.

• Identification: Look for the manufacturer stamp 975178BA or 3SA131191K on the casing of the catalytic body itself.

Secondary Catalytic Converters (Lower/Intermediate)

Further down the exhaust stream, these units provide additional filtration and particulate trapping (GPF/OPF in European models).

• Left Secondary: 3SA254300A (or similar depending on market)

• Right Secondary: 3SA254350B (often listed as 3SA254351B)

W12 “Kit” Components

When replacing these converters as a “kit,” Bentley standards generally require several one-time-use hardware pieces to ensure a leak-free seal:

1. V-Band Clamps: These secure the primary cat to the turbocharger outlet.

2. Oxygen (Lambda) Sensors: Each bank (1-6 and 7-12) uses pre-cat and post-cat sensors.

   • Standard Part: 07C906262AT

3. Manifold Gaskets: If the catalytic converter is being replaced due to a manifold leak, new gaskets are mandatory.

Common Service Issues (2018–2024)

• OPF Monitoring: On models from 2019 onward (especially in the UK/EU), the secondary cats often contain an Otto Particulate Filter (OPF). If these become clogged, the car will enter a “Reduced Power” mode.

• Sensor Cross-Contamination: Because the W12 engine bay is extremely tight, wiring harnesses for the Lambda sensors can sometimes suffer from heat damage, causing false “Catalyst Inefficient” codes.

• The “Hot V” Effect: While the W12 isn’t a traditional “Hot V” like the 4.0L V8, the primary cats sit in a high-heat zone at the rear of the engine block. Heat shield integrity is vital to prevent fire risks or damage to the firewall insulation.