Engine-CodesGeneric – P0299

P0299 Code - Engine Underboost

Quick Answer

The P0299 diagnostic trouble code (DTC) indicates that the engine is underboost, meaning that the amount of boost pressure in the intake manifold is lower than the manufacturer-specified level. Common causes include Boost leak: A leak in the intake system, such as a cracked hose or loose connection, can lead to a loss of boost pressure, Wastegate malfunction: The wastegate controls the flow of exhaust gases to the turbocharger, and if it malfunctions, it can result in an underboost condition, Turbocharger failure: A worn-out or damaged turbocharger can fail to provide the required boost pressure. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P0299 indicates Engine Underboost.
Common causes
Common causes include Boost leak: A leak in the intake system, such as a cracked hose or loose connection, can lead to a loss of boost pressure, Wastegate malfunction: The wastegate controls the flow of exhaust gases to the turbocharger, and if it malfunctions, it can result in an underboost condition, Turbocharger failure: A worn-out or damaged turbocharger can fail to provide the required boost pressure.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Table of contents Created and updated by William Orellana on Sep 06, 2024
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Code P0299 Description

The P0299 diagnostic trouble code (DTC) indicates that the engine is underboost, meaning that the amount of boost pressure in the intake manifold is lower than the manufacturer-specified level. This can lead to a decrease in engine performance, reduced fuel efficiency, and potential damage to various engine components if not addressed promptly. When a turbocharged engine operates, the turbocharger compresses the intake air to increase power output. If the engine is underboosting, it means that the turbocharger is not providing enough boost pressure, which can result from a variety of issues such as a leak in the intake system, a malfunctioning wastegate, a faulty turbocharger, or a problem with the boost control system.

OBDII Code P0299 - Engine Underboost
P0299 Code - Engine Underboost

Common Causes of P0299

  1. Boost leak: A leak in the intake system, such as a cracked hose or loose connection, can lead to a loss of boost pressure.
  2. Wastegate malfunction: The wastegate controls the flow of exhaust gases to the turbocharger, and if it malfunctions, it can result in an underboost condition.
  3. Turbocharger failure: A worn-out or damaged turbocharger can fail to provide the required boost pressure.
  4. Boost control system issue: Problems with the boost control solenoid, vacuum lines, or electronic boost control system can lead to an underboost condition.

Symptoms of P0299

  1. Reduced engine power: The vehicle may feel sluggish and have difficulty accelerating.
  2. Decreased fuel efficiency: An engine underboost condition can lead to an increase in fuel consumption.
  3. Illuminated check engine light: The P0299 DTC will trigger the check engine light to come on.
  4. Engine misfires: Underboost can cause the engine to run lean, resulting in misfires and rough idling.

How to Fix P0299

  1. Inspect the intake system: Check for any leaks in the intake system, including hoses, intercooler connections, and gaskets. Repair or replace any damaged components.
  2. Test the wastegate: Verify that the wastegate is functioning correctly and adjusting the boost pressure as needed. Replace the wastegate if it is faulty.
  3. Check the turbocharger: Inspect the turbocharger for any signs of damage or wear. If necessary, replace the turbocharger to restore proper boost pressure.
  4. Diagnose the boost control system: Test the boost control solenoid, vacuum lines, and electronic boost control system to identify any issues. Repair or replace components as required to ensure proper boost regulation.

Cost to Fix P0299

The cost of repairing an engine underboost issue can vary depending on the specific cause of the problem and the make and model of the vehicle. In general, the cost of parts for repairs related to the P0299 code can range from $200 to $1000, with labor costs adding an additional $100 to $500. Keep in mind that the actual cost may be higher or lower based on the extent of the repairs needed and the rates charged by the auto repair shop. It is recommended to obtain a detailed estimate from a qualified mechanic to determine the precise cost of addressing the engine underboost issue in your vehicle.

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Code P0299 Information for Specific Makes

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

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