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.
2018 Subaru WRX BaseFACTORY OEM SERVICE PROCEDURE
Knock Sensor: Installation
WARNING: This page is about a different variant/trim than selected.
- 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)
- Install the secondary air combination valve RH. Ref. to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (STI)>Secondary Air Combination Valve>INSTALLATION>SECONDARY AIR COMBINATION VALVE RH .
- Install the intake manifold. Ref. to FUEL INJECTION (FUEL SYSTEMS) (STI)>Intake Manifold>INSTALLATION .
- Install the intercooler. Ref. to INTAKE (INDUCTION) (STI)>Intercooler>INSTALLATION .
- Connect the battery ground terminal.
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.