Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
SYS.OK|MANUAL.DBβ LIVE
HOMESERVICE MANUALSSUBARU2012IMPREZA WRX STI F4-2.5L DOHC TURBOREPAIR AND DIAGNOSISPOWERTRAIN MANAGEMENTCOMPUTERS AND CONTROL SYSTEMSSENSORS AND SWITCHES - COMPUTERS AND CONTROL SYSTEMSKNOCK SENSORSERVICE AND REPAIR
2012 Subaru Impreza WRX STI F4-2.5L DOHC Turbo
Knock Sensor: Service and Repair
2012 Subaru Impreza WRX STI F4-2.5L DOHC TurboSECTION Service and Repair
Knock Sensor
REMOVAL
1. Disconnect the ground cable from battery.

2. Remove the intercooler.
3. Remove the intake manifold.
4. Remove the secondary air combination valve RH.
5. Remove the knock sensor from cylinder block.

INSTALLATION
1. Install the knock sensor to the cylinder block.
NOTE: The portion of the knock sensor cord that is pulled out must be positioned at a 60° angle relative to the engine rear.
Tightening torque: 24 N.m (2.4 kgf-m, 17.7 ft-lb)

2. Install the secondary air combination valve RH.
3. Install the intake manifold.
4. Install the intercooler.
5. Connect the battery ground terminal.

REMOVAL
1. Disconnect the ground cable from battery.
2. Remove the intercooler.
3. Remove the intake manifold.
4. Remove the secondary air combination valve RH.
5. Remove the knock sensor from cylinder block.
INSTALLATION
1. Install the knock sensor to the cylinder block.
NOTE: The portion of the knock sensor cord that is pulled out must be positioned at a 60° angle relative to the engine rear.
Tightening torque: 24 N.m (2.4 kgf-m, 17.7 ft-lb)
2. Install the secondary air combination valve RH.
3. Install the intake manifold.
4. Install the intercooler.
5. Connect the battery ground terminal.
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.