Parts for your 2015 Subaru Exiga-Knock sensor

2015 Subaru Exiga knock sensor — what it does, and when to sort it

Yes, the 2015 Subaru Exiga is fitted with a knock sensor. Subaru’s service information for the YA‑series Exiga (as supplied through the Subaru Technical Information System service manuals) shows a knock sensor mounted to the cylinder block, and the Subaru FAST parts catalogue lists a dedicated knock sensor for the 2015 Exiga engines used in Australia and New Zealand markets (EJ/FB family). OBD‑II diagnostic coverage for this model year also includes knock sensor fault codes (such as P0325), further confirming it’s part of the factory setup.

The knock sensor’s job is straightforward but critical. It listens for knock (pinging) — those sharp vibration signatures that happen when the air‑fuel mix detonates too early. When it hears trouble, it tells the ECU to trim ignition timing and protect the engine. That keeps the Exiga running smoothly on everyday petrol, helps maintain power on hills, and protects the internals from long‑term damage. It also helps fuel economy by letting the ECU run as much timing as the engine safely allows.

There’s no scheduled replacement interval for the knock sensor, but it’s smart to check it during regular services — especially once the kilometres start piling up. A technician will usually eyeball the harness and connector for heat hardening, oil contamination under the bonnet, or any tell‑tale green corrosion. If it ever needs replacing, correct fitment is everything: the mounting boss must be clean and dry, and the sensor should be tightened to the factory torque so it reads vibration accurately. Over‑ or under‑tightening can make it “hear” the wrong things.

• Common symptoms of a crook knock sensor on a 2015 Exiga:
  • Check Engine Light with codes like P0325
  • Lazier throttle response and reduced power (failsafe timing)
  • Pinging under load or uphill
  • Worse fuel economy than usual

Replacement is a tidy job for a pro, but keen DIYers can manage with care. Always disconnect the battery, remove the necessary intake bits for access, swap the sensor and correctly orient it per the service manual, torque it to spec, reconnect, clear codes and do a proper road test on varied loads. Running the correct octane for local conditions, fixing intake leaks promptly, and keeping engine mounts in good nick all help the sensor do its best work.

Popular questions about 2015 Subaru Exiga knock sensors

Does the 2015 Exiga definitely have a knock sensor?
It does. Subaru service manuals for the 2015 YA‑series and the Subaru FAST parts catalogue both include a cylinder‑block‑mounted knock sensor for the Exiga’s EJ/FB engines. The model’s diagnostic coverage also includes knock‑sensor‑related OBD‑II codes.

Is it safe to drive if the knock sensor code pops up?
The car will usually pull ignition timing to protect the engine, so it may feel down on power and chew a bit more fuel. Short trips to a workshop are typically fine, but it’s best not to push it under heavy load until the fault is diagnosed and fixed.

What’s the typical replacement approach?
Inspect wiring first. If the sensor is confirmed faulty, it’s removed from the block, the mounting surface is cleaned, then a new sensor is installed and torqued to the factory spec with the correct orientation. Clear the code and road test to confirm.