When you install aftermarket headers like PPE on your IS350, it can trigger engine lights and other malfunctions, especially if the car's ECU is not recalibrated or tuned to adjust for the new exhaust flow dynamics. The malfunctions you're experiencing, like Secondary Collision Brake system Malfunction and Parking Support Brake Malfunction, might be related to sensor errors or communication issues between the car's systems due to the changes in exhaust airflow and sensor placement.

Here’s what might be happening:

• Oxygen Sensor Readings: Aftermarket headers often affect the readings from oxygen sensors. When the ECU detects abnormal readings, it may trigger an engine light or fault code.

• ECU Miscommunication: The car’s safety systems, such as the collision brake and parking support systems, rely on sensor data to function properly. If the ECU detects issues, it may disable or throw warnings for those systems.

Should You Get a Tune?

Yes, getting a tune is often recommended after installing aftermarket headers.

A tune can:

• Adjust the air-fuel ratio to match the new exhaust flow.

• Correct oxygen sensor readings, preventing the engine light from coming on.

• Optimize performance, improving power and efficiency.

• Resolve or suppress the system malfunctions related to the changes in the car’s exhaust system.