P0299: Turbocharger/Supercharger "A" Underboost Condition
Moderate SeveritySafe to drive (short-term)Fuel System
P0299 means the turbocharger is not producing enough boost pressure to meet the ECU's target value during normal driving. The engine will feel noticeably less powerful, especially under acceleration. Common causes include boost leaks in the charge piping, a stuck-open wastegate, or a worn turbocharger with failing bearings.
What does P0299 mean?
P0299 means the turbocharger is not producing enough boost pressure to meet the ECU's target value during normal driving. The engine will feel noticeably less powerful, especially under acceleration. Common causes include boost leaks in the charge piping, a stuck-open wastegate, or a worn turbocharger with failing bearings.
P0299 is a fuel system-related diagnostic trouble code classified as moderate severity. When your vehicle's ECU detects this condition, it stores P0299 and illuminates the check engine light.
What are the symptoms of P0299?
If your vehicle has triggered P0299, you may notice one or more of these symptoms:
Check engine light on
Significant loss of power and acceleration
Limp mode (reduced engine power warning)
Turbo whistle absent or reduced
Black smoke from exhaust under acceleration
Higher than normal exhaust gas temperatures
What causes P0299?
Here are the most common causes of P0299, ranked by how likely they are to be the culprit:
mediumClogged air filter restricting airflow to turbo
mediumFaulty boost control solenoid
lowBlocked catalytic converter or DPF creating exhaust backpressure
Is it safe to drive with P0299?
Generally yes, for short-term driving. You can drive to a workshop but expect significantly reduced power. The engine is not in immediate danger but the underlying cause should be repaired soon to prevent further turbo damage.
How do you diagnose P0299?
Follow these steps to pinpoint the root cause of P0299:
Use a scan tool to monitor actual boost pressure versus target boost. If actual pressure is consistently 0.3+ bar below target under load, the underboost is confirmed
Check the air filter first. A severely clogged filter restricts airflow and limits boost. Replace if dirty
Perform a boost leak test by pressurising the intake system with compressed air (0.5-1 bar) and listening/feeling for leaks at intercooler pipes, hose connections, and the intercooler itself
Inspect the wastegate by checking if the actuator rod moves freely. Disconnect the vacuum/pressure line and verify the wastegate closes fully. A stuck-open wastegate allows exhaust to bypass the turbo
Check the turbo for shaft play by removing the intake pipe and wiggling the compressor wheel. More than 1 mm of radial play indicates worn bearings
If no boost leaks or turbo wear found, check for exhaust restrictions (blocked DPF or catalytic converter) using a backpressure test
How much does P0299 cost to fix?
Repair costs for P0299 vary depending on the root cause and your vehicle. Here are typical estimates:
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Fix boost leak (tighten clamps, replace hose)
€10–€80
€30–€120
€40–€200
Moderate
Replace air filter
€10–€30
€10–€20
€20–€50
Easy
Replace boost control solenoid
€20–€80
€30–€90
€50–€170
Easy
Replace or repair wastegate actuator
€60–€250
€80–€250
€140–€500
Professional
Replace turbocharger
€400–€1500
€300–€800
€700–€2300
Professional
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0299 on specific vehicles
P0299 behaves differently depending on your vehicle. Select your car below for model-specific causes, known issues, and adjusted cost estimates:
P0299 on Volkswagen Golf
Volkswagen Golf • 2005-2024
The 1.4 TSI and 2.0 TDI are frequent triggers for P0299. The plastic charge pipes on the EA888 can crack in cold weather, causing boost leaks. The 2.0 TDI often suffers from turbo actuator failures and DPF-related backpressure. Check the N75 valve and all boost hose connections.
What causes P0299 on a Volkswagen Golf?
Volkswagen GolfCracked plastic charge pipe on EA888 engines in cold weather
Volkswagen GolfTurbo actuator failure on 2.0 TDI (especially CR engines)
P0299 repair cost for Volkswagen Golf
Estimated costs for Volkswagen Golf ownersadjusted higher than average due to Volkswagen-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Fix boost leak (tighten clamps, replace hose)
€11–€88
€33–€132
€44–€220
Moderate
Replace air filter
€11–€33
€11–€22
€22–€55
Easy
Replace boost control solenoid
€22–€88
€33–€99
€55–€187
Easy
Replace or repair wastegate actuator
€66–€275
€88–€275
€154–€550
Professional
Replace turbocharger
€440–€1650
€330–€880
€770–€2530
Professional
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0299 on Ford Focus
Ford Focus • 2010-2024
The 1.0 EcoBoost is known for turbo failures at higher mileages due to coolant feed line issues causing oil coking. P0299 on EcoBoost engines can be the first sign of turbo bearing wear. The 1.5 and 2.0 EcoBoost in ST/RS models can develop intercooler leaks.
What causes P0299 on a Ford Focus?
Ford FocusTurbo bearing wear on 1.0 EcoBoost from coolant line issues
Ford FocusIntercooler pipe leaks on 1.5/2.0 EcoBoost ST models
P0299 on Skoda Octavia
Skoda Octavia • 2008-2024
Shares the VW 1.4 TSI and 2.0 TDI engines. The same boost leak and turbo actuator issues apply. Skoda uses slightly different charge pipe routing which can have different failure points. The 1.8 TSI in the Octavia RS is also susceptible to wastegate issues.
What causes P0299 on a Skoda Octavia?
Skoda OctaviaBoost hose connections loosening on 1.4 TSI
Skoda OctaviaWastegate actuator failure on 2.0 TDI
P0299 on Peugeot 308
Peugeot 308 • 2007-2024
The 1.6 THP (EP6DT) turbo engine is known for oil feed line coking that leads to turbo failure. P0299 can be an early warning sign. The 1.6 BlueHDi diesel can also develop P0299 from DPF back-pressure issues or turbo actuator faults.
What causes P0299 on a Peugeot 308?
Peugeot 308Turbo oil feed line coking on 1.6 THP causing bearing wear
Peugeot 308DPF back-pressure causing underboost on 1.6 BlueHDi
P0299 repair cost for Peugeot 308
Estimated costs for Peugeot 308 ownersadjusted higher than average due to Peugeot-specific parts pricing
Repair
Parts Cost
Labor Cost
Total Estimate
DIY Difficulty
Fix boost leak (tighten clamps, replace hose)
€11–€84
€32–€126
€42–€210
Moderate
Replace air filter
€11–€32
€11–€21
€21–€53
Easy
Replace boost control solenoid
€21–€84
€32–€95
€53–€179
Easy
Replace or repair wastegate actuator
€63–€263
€84–€263
€147–€525
Professional
Replace turbocharger
€420–€1575
€315–€840
€735–€2415
Professional
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
Related diagnostic codes
These codes are often seen alongside P0299 or indicate related issues:
P0299 means the turbocharger is not generating enough boost pressure to meet the ECU's target. The engine will feel noticeably less powerful. This can be caused by boost leaks, a wastegate fault, turbo wear, or airflow restrictions.
Can I drive with P0299?
Yes, but with significantly reduced power. The engine is not in immediate danger from underboost itself. However, the underlying cause (such as turbo bearing wear) can worsen. Drive to a workshop but avoid heavy loads or towing.
What is the most common cause of P0299?
Boost leaks are the most common cause. A loose hose clamp, cracked intercooler pipe, or split silicone coupler can allow pressurised air to escape before reaching the engine. These are often the cheapest and easiest fix.
How do I check for boost leaks?
The most reliable method is a boost leak test. Block the throttle body inlet, connect compressed air at low pressure (0.5-1 bar), and listen or use soapy water to find leaks. Common leak points are intercooler pipe connections, charge pipe joints, and the intercooler itself.
How much does it cost to fix P0299?
Fixing a boost leak costs 40-200 EUR. A boost solenoid replacement runs 50-170 EUR. Wastegate repair is 140-500 EUR. If the turbo itself is worn out, replacement costs 700-2,300 EUR including parts and labour.
