P0299 on Citroen: How to Diagnose & Fix
Turbo/Supercharger Underboost Condition
1 Citroen model · 1 documented issue · 1 critical · $400-$1,500 repair
P0299 on Citroen by model: symptoms, diagnosis and fix
The DS3 THP turbocharger develops oil leaks from the oil feed and return pipes, and the turbo bearing seals degrade over time. Oil consumption increases and blue smoke is visible under boost and on the overrun.
Common Symptoms
- Blue smoke under boost
- Increased oil consumption
- Oil around turbo
- Turbo whistle change
How to Fix
Replace turbo oil feed and return lines with updated gaskets. Rebuild or replace the turbocharger if shaft play is detected. Maintain strict oil change intervals.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- NTY ECD/CT/002A turbocharger oil-feed pipe with banjo hardware
replace a confirmed leaking or disturbed OE 037956 pressurized turbo oil-feed line Fitment/availability: Citroen DS3 1.6 THP 155 2010-2015, DS3 Racing 2011-2015 and listed convertible branches; OE 0379.56/037956/9824001880, includes banj…
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Sources for this issue (3)
P0299 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0299 mean on a Citroen?
P0299 stands for "Turbo/Supercharger Underboost Condition." P0299 means the engine computer detected an underboost condition — the turbocharger or supercharger is producing less boost pressure than the PCM expects for the given conditions. The computer compares the manifold/boost pressure sensor reading to a target based on engine load, and when actual boost falls short, it sets this code. The most common real-world cause is a leak somewhere in the intake/charge-air path. You'll typically feel reduced power or sluggish acceleration, and the engine may go into a reduced-power mode. On Citroen it is documented across 1 model: DS3.
What are the most common causes of P0299?
The most common causes of P0299 are: Boost/intake leak (cracked or loose charge-air hose or intercooler), Faulty or sticking turbo wastegate or actuator, Stuck or clogged variable-geometry turbo vanes (VGT), Faulty boost pressure or MAP sensor, Leaking or disconnected vacuum/boost control lines, Restricted air intake or clogged air filter, Failed boost control solenoid, Worn or failing turbocharger. The specific cause varies by vehicle.
How much does it cost to fix P0299 on a Citroen?
Published repair estimates on Citroen range from $400 to $1,500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.