Parts for your 2016 Subaru Forester-Knock sensor

2016 Subaru Forester Knock Sensor

Yes, the 2016 Subaru Forester is fitted with a knock sensor and relies on it for proper engine control. This is confirmed by factory technical documentation that lists diagnostic trouble codes for the knock sensor circuit and shows the sensor mounted to the engine block. Technical sources include: Subaru Forester (SJ, MY2016) Factory Service Manual – Engine (Diagnostics) sections covering DTC P0325, P0327 and P0328, Subaru Technical Information System (STIS) service publications for FB25 2.5i and FA20F 2.0XT engines, and OEM parts catalogues that specify a knock sensor for these engines.

On the 2016 Forester, the knock sensor’s job is to “listen” for detonation (knock) in the cylinders and let the engine control unit trim ignition timing to keep things safe and smooth. Whether it’s the 2.5‑litre FB25 or the turbocharged 2.0‑litre FA20F, the sensor helps the ECU optimise spark for Aussie and Kiwi pump fuels, from regular 91 RON through to premium. That means better drivability, less risk of engine damage under load, and improved fuel efficiency on the school run or a long haul up the coast.

This part isn’t a regular service item, so there’s no scheduled replacement interval. It’s a “fit and forget” component until there’s a reason to look at it. Typical prompts include a check engine light with a knock sensor code, a bit of pinging under load, sluggish performance, or unexpectedly high fuel use. A proper scan will usually flag one of the common codes—P0325, P0327 or P0328—when the sensor or its wiring isn’t happy.

When replacement is needed, the best approach is straightforward and careful:

• Scan, confirm the fault and rule out fuel quality issues or other engine problems first.
• Visually check the harness and connector for damage, oil contamination or corrosion.
• Only install a quality OEM‑spec sensor. Cheap copies can trigger false knock or miss real events.
• Clean the mounting pad on the block, fit the sensor in the correct orientation as specified in the factory manual.
• Tighten to the factory torque using a torque wrench—overtightening can ruin a new sensor.
• Clear codes, perform a proper drive cycle and recheck live data to confirm timing correction looks normal.

Location‑wise, the sensor is bolted to the engine block beneath the intake area. Access varies by model and tools, so many owners leave this job to a workshop with the right service information. Get it right and the Forester runs sweeter, pulls harder, and keeps the engine safe when conditions get tough.

Popular questions about 2016 Subaru Forester knock sensors

What are the symptoms of a bad knock sensor on a 2016 Forester?
Common signs include a check engine light (often with codes P0325, P0327 or P0328), pinging under load, flat or hesitant acceleration, and higher‑than‑usual fuel use. The ECU may pull timing to protect the engine, which feels like a lack of grunt.

Is it safe to drive with a faulty knock sensor?
It will usually run, but the ECU may default to conservative timing, so performance and economy suffer. If detonation is actually occurring, there’s a risk of engine damage. Best to get it diagnosed and sorted promptly.

Where is the knock sensor on a 2016 Forester?
It’s mounted to the engine block under the intake area, roughly central on the block. Access can be tight, following the factory service manual procedure helps avoid broken clips, mis‑orientation or incorrect torque.