Symptoms:

• Reduced engine performance
• Insufficient turbocharger pressure
• Check engine light

Causes:

• Faulty exhaust back pressure valve
• Opened or shorted exhaust back pressure valve
• Poor electrical connection in the exhaust back pressure valve circuit
• Faults in the exhaust back pressure
• Engine oil temperature
• Intake air temperature sensors

Possible Solutions:

• Unclogging or repairing the back pressure tube
• Cleaning, repairing or replacing the exhaust back pressure sensor
• Repairing or replacing a faulty exhaust back pressure valve
• Repairing or replacing an opened or shorted exhaust back pressure valve
• Repairing a poor electrical connection in the exhaust back pressure valve circuit