Turbo underboost on Toyota — 2.0/2.2 D-4D and 1.2T Yaris/Auris hybrid turbo charge-pipe and actuator issues.
Toyota P0299 — Turbo underboost on Toyota — 2.0/2.2 D-4D and 1.2T Yaris/Auris hybrid turbo charge-pipe and actuator issues. Typical UK independent garage cost: £180–£1400.
What actually causes P0299 on a Toyota
Toyota 2.0/2.2 D-4D P0299 is usually a perished EGR-to-turbo charge pipe, occasionally a sticking VGT vane assembly (cleanable). The 2.2 D-4D head-gasket recall era cars need careful diagnosis before authorising turbo work.
Toyota engines that log P0299
- 2.0 D-4D 1AD-FTV (Avensis/Auris)
- 2.2 D-4D 2AD-FTV (RAV4/Avensis)
- 1.2T 8NR-FTS (Auris)
How we diagnose P0299 on a Toyota
- Compression test before turbo work on 2AD-FTV
- Smoke-test charge air
- VGT actuator sweep
- Inspect EGR cooler
The common misdiagnosis to avoid
Don't replace the turbo on 2.2 D-4D without a compression test — head-gasket failure presents similar symptoms.
Toyota P0299 repair cost in the UK
Expect £180–£1400 including parts and labour at an independent garage. Main-dealer quotes on Toyota 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
Auris 2.0 D-4D P0299 — EGR cooler hose at the back of the engine is the usual culprit. Cheap fix when you find it.
Codes usually seen alongside P0299 on Toyota
- P0234
- P2563
Symptoms drivers report with P0299
- Loss of power above 2,000–2,500 RPM — car feels flat overtaking on the motorway
- Limp mode kicks in at 3,000 RPM, resets after a key cycle, then returns within 10 miles
- Whistling from engine bay under load — split intercooler pipe or Y-piece
- Black smoke or fuel smell from the exhaust on diesels — VNT stuck open, over-fuelling
- Paired codes: P0234 (overboost, VNT stuck closed), P0299 with P0401 (EGR + boost overlap), P0299 with P132B (turbo boost control)
Repairs that clear P0299
- Smoke-test the boost system first (cheap and finds most causes)
- Clean VNT vanes with rocker-arm actuation
- Replace boost sensor
- Replace turbo as last resort
For the generic, all-makes explanation of this code — meaning, every known cause and UK cost bands — see our P0299 guide.
Reading P0299 on a Toyota properly
A generic reader will show P0299 and nothing else. What matters is the freeze-frame data stored with it — engine speed, load, coolant temperature and fuel trims at the moment the fault was logged — plus whether any other module on the Toyota has logged something at the same time. Codes rarely arrive alone, and the order they were stored in usually points at which one is the cause and which are the consequences.
Clearing P0299 without fixing it
Erasing the code resets the Toyota's readiness monitors as well as the light. The fault returns on the next drive cycle if the cause is still there, and in the meantime the incomplete monitors can stop the car passing an emissions check. After a genuine repair, the car is driven until the relevant monitor completes before it is handed back.
Bob's Mechanical Repairs is an independent garage in Birnam, Dunkeld, Perthshire, with 32 years of Bob's experience on the tools. If P0299 is showing on your Toyota, bring any scan results with you — we will read the live data ourselves, confirm which cause it actually is, and price the repair before any work starts.