P0299: Turbocharger/Supercharger Underboost Condition
Can you still drive? Yes, but with reduced power. The vehicle is safe to drive but performance will be significantly diminished. Avoid towing or heavy loads.
What Does P0299 Mean?
Code P0299 indicates that the turbocharger or supercharger is not producing the expected amount of boost pressure. The ECM monitors the difference between target and actual boost and sets this code when actual boost is significantly below target. This results in reduced engine performance and is common on turbocharged vehicles with higher mileage.
Need to read your codes?
An OBD-II scanner lets you read and clear diagnostic trouble codes from your vehicle's computer. Most scanners work with any car made after 1996.
Browse OBD-II Scanners on AmazonCommon Causes
- Boost pressure leak in intercooler piping
- Worn turbocharger with shaft play
- Stuck-open wastegate
- Leaking charge air cooler (intercooler)
- Failed boost pressure sensor
Symptoms
- Check engine light on
- Noticeable loss of power
- Sluggish acceleration
- Engine may enter limp mode
- Possible whistling or hissing from a boost leak
Diagnostic Steps
- 1Check all intercooler pipes, clamps, and couplers for leaks
- 2Perform a boost leak test using a pressure tester on the intake tract
- 3Inspect turbocharger for shaft play by grabbing the compressor wheel
- 4Verify wastegate closes fully when no vacuum is applied
- 5Check boost pressure sensor readings with a scan tool
- 6Inspect intercooler for cracks or damage
Recommended Parts & Tools
boost leak tester
intercooler coupler set
silicone coupler clamps
Estimated Repair Cost
| Type | Estimated Cost |
|---|---|
| Total Repair Cost Range | $100 - $2500 |
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Chat with AI About P0299Commonly Affected Vehicles
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Frequently Asked Questions
What causes underboost?
Underboost is most commonly caused by a boost leak somewhere in the intake piping between the turbo and the engine. A worn turbo with excessive shaft play is another common cause on higher-mileage vehicles.
How do I check for a boost leak?
A boost leak tester pressurizes the intake tract and allows you to listen or spray soapy water to find leaks at couplers, intercooler connections, or cracked pipes. This is the most effective diagnostic method.
Community Fix Reports
Community reports are user-submitted and not verified by Auto AI Buddy. Results may vary.
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