Turbocharger/Supercharger B Underboost Condition

Common symptoms

What you'll notice

• Check for any vacuum leaks in the intake system and repair if necessary.
• Inspect and clean the turbocharger or supercharger to ensure proper functioning.
• Check the operation of the wastegate or bypass valve and repair or replace if faulty.
• Inspect and replace any damaged or worn turbocharger/supercharger components.
• Check and repair any issues with the air intake system, such as a clogged air filter or restricted airflow.

Common causes

Most likely first

1. Faulty wastegate or actuator
2. Boost pressure leak or restriction
3. Faulty turbocharger/supercharger
4. Restricted intake or exhaust system
5. Malfunctioning boost control solenoid

How to diagnose & fix

Work through it in order

1. Decreased engine power or loss of power
2. Poor acceleration or slow throttle response
3. Engine misfires or rough idle
4. Increased fuel consumption
5. Check Engine Light (CEL) or "Service Engine Soon" warning light is illuminated