Bank 2 cat efficiency on VAG V6 — 3.0 TFSI supercharged and 2.0 TDI BiTDI rear O2 sensor or upstream coolant ingestion.
Volkswagen P0430 — Bank 2 cat efficiency on VAG V6 — 3.0 TFSI supercharged and 2.0 TDI BiTDI rear O2 sensor or upstream coolant ingestion. Typical UK independent garage cost: £260–£2400.
What actually causes P0430 on a Volkswagen
VAG 3.0 TFSI mirrors the Audi story — coolant leak from the plastic thermostat housing destroys bank-2 cats. On 3.0 V6 TDI it's usually a lazy rear O2 sensor before the cat itself fails. Confirm with VCDS rear O2 switching data before quoting.
Volkswagen engines that log P0430
- 3.0 TFSI supercharged (Touareg/Phaeton)
- 3.0 V6 TDI CR (Touareg/Phaeton)
- 3.2 VR6 FSI
How we diagnose P0430 on a Volkswagen
- Identify bank 2 (passenger side RHD)
- Rear O2 voltage swing test
- Check coolant level history
- Smoke-test exhaust upstream
The common misdiagnosis to avoid
Garages quote both cats — bank 2 only on V6 unless live data proves otherwise.
Volkswagen P0430 repair cost in the UK
Expect £260–£2400 including parts and labour at an independent garage. Main-dealer quotes on Volkswagen are usually higher for the same job, and the spread exists because the cheap cause and the expensive cause throw the same code — pay for the diagnosis before you pay for parts.
Bob's workshop tip
Touareg 3.0 TFSI P0430 — check the thermostat housing before condemning the cat.
Codes usually seen alongside P0430 on Volkswagen
- P0420
- P2096
Symptoms drivers report with P0430
- MIL comes on after a motorway run then stays lit — no drivability change
- Slight sulphur/rotten-egg smell on hard acceleration
- MPG drop of 1–3 mpg you wouldn't notice unless you track it
- Fails emissions/lambda snapshot at MOT despite passing tailpipe CO
- Bank 2 short-term fuel trim slightly richer than bank 1 at cruise
Repairs that clear P0430
- Same diagnostic as P0420 but bank 2 side
- Replace bank 2 rear lambda first as trial
- Confirm with lambda graphing before cat replacement
For the generic, all-makes explanation of this code — meaning, every known cause and UK cost bands — see our P0430 guide.