22060AA111 Subaru SEN ASSY-KNOCK, Price: 45.22$, Weight: 0.053kg

Engine Knock Detection Sensor Assembly

This sensor assembly is a small but critical guard for your Subaru engine. It is needed to detect abnormal combustion (knock/ping) that can damage pistons, rings, and bearings over time. By “listening” to vibration on the engine block, it helps the ECU keep power strong while protecting the motor 🔧.

How It Works

Inside is a piezoelectric element that converts engine vibration into a voltage signal. The ECU reads this signal and, when knock is detected, adjusts ignition timing (and sometimes fuel strategy) to stop the harmful rattle. When conditions are normal, the ECU allows more efficient timing for better response and economy ⚙️.

Why Replacement Matters

If the sensor is cracked, loose, or electrically weak, the ECU may get false readings or no signal at all. This can cause reduced power, poor acceleration, higher fuel use, hesitation, and a check engine light. In worst cases, real knock can go unnoticed and lead to serious internal engine damage 🚗.

Common Signs of Failure

• Check engine light related to knock signal
• Sluggish performance or timing pulled back
• Pinging under load or climbing

Compatibility

• Legacy
• Impreza
• Forester