Parts for your 2016 Subaru Exiga-Knock sensor

2016 Subaru Exiga knock sensor – what it does and when to replace it

Based on technical references — the Subaru Factory Service Manual (Engine section: FB20) and Subaru’s FAST electronic parts catalogue for the 2015–2017 Exiga/Exiga Crossover 7 — the 2016 Subaru Exiga is fitted with a knock sensor. It’s a piezoelectric sensor mounted to the engine block, used by the ECU to detect detonation and adjust ignition timing.

On a 2016 Exiga running the FB20 2.0‑litre boxer, the knock sensor listens for the high-frequency “ping” of detonation. When it hears anything dodgy, the ECU trims timing to protect the engine. That means cleaner running, better fuel economy, and strong reliability on our varied Aussie and Kiwi fuels. If the sensor is unhappy or its signal is off, the car may feel flat, use more fuel, or log a check engine light with knock‑sensor fault codes (often P0325–P0328).

It’s not a routine replacement item, most live the life of the engine. During scheduled servicing, a good workshop will visually check the sensor area and harness for oil contamination, brittle conduit, or a loose connector. Any hint of intermittent knock codes, audible pinging under load, or unexplained timing pull on a scan tool is a cue to test the sensor circuit.

When replacement is needed, it’s a straightforward job for a tech familiar with Subarus:

• Confirm diagnosis with scan data and wiring checks (don’t shotgun parts).
• Mount the new sensor to a clean, dry block surface with the correct orientation and torque, overtightening or twisting the body can ruin a brand-new unit.
• Avoid thread sealants, they can alter the signal path and sensitivity.
• Clear codes and road-test, checking knock correction and feedback on a scan tool to confirm it’s behaving.

DIY owners can do it, but access is under the intake area on the block, so allow time and follow torque/orientation specs from the service manual. Use quality OEM‑equivalent parts, cheap copies can be noisy or insensitive, leading to false knock or, worse, missed detonation. If the Exiga’s been running on low‑octane fuel or has carbon build-up, fixing those contributors goes hand in hand with knock-sensor health. Treated right, the sensor quietly keeps the FB20 safe while you clock up the kilometres.

• Where is the knock sensor on a 2016 Exiga?
  It’s mounted on the engine block beneath the intake manifold area. Access is typically from above with intake plumbing/components moved aside. A service manual helps with the exact orientation and torque spec.
• Can it be driven with a bad knock sensor?
  The ECU usually runs conservative timing to protect the engine, so it’ll feel sluggish and use more fuel. If real knock is occurring and the sensor can’t report it, there’s a risk of engine damage. Best to diagnose and fix promptly.
• Does the knock sensor need routine replacement?
  No set interval. It’s inspected during normal servicing and replaced only if faulty or contaminated, or if wiring damage is found and testing confirms an issue.