Parts for your 2014 Subaru Exiga-Knock sensor

2014 Subaru Exiga knock sensor — what it does and when to replace it

Yes, the 2014 Subaru Exiga uses a knock sensor. This is confirmed by Subaru’s Factory Service Manual for the YA-series Exiga (engine control section notes knock sensing and self-diagnostics), Subaru’s FAST parts catalogue listing a knock sensor for 2014 Exiga chassis, and OE supplier documentation for Denso piezoelectric knock sensors used on EJ/FB petrol boxer engines. The sensor is mounted on the cylinder block under the intake manifold and feeds knock data to the ECU so timing can be trimmed on the fly.

On the 2014 Exiga, the knock sensor’s job is to “listen” for high-frequency vibration that points to detonation (pinging). When it hears knock, it signals the ECU to gently pull ignition timing to protect the engine. That means smoother running on variable fuel quality across NZ and Australia, better longevity under load, and fewer hiccups when towing or tackling hills. If it’s dull, damaged, or mis-torqued, the ECU may default to safer timing, making the car feel flat and using more fuel, or worse, it may miss real knock events.

There’s no routine replacement interval for the Exiga’s knock sensor—Subaru treats it as a monitor-and-repair item. As part of scheduled servicing, a good workshop will:

• Scan for fault codes such as P0325, P0327 or P0328, and check live knock correction values.
• Inspect the sensor connector and harness routing for heat damage, oil contamination, or chafing under the intake manifold.
• Verify the sensor is correctly seated on a clean, dry block surface and tightened to the factory torque (over-tightening will skew readings).

Replacement is straightforward for a trained tech and usually takes about an hour depending on intake access. Best practice is to use a genuine-quality sensor, clean the mounting pad on the block, install the sensor dry (no grease or thread tape), route the loom away from sharp edges and heat, and torque it to spec with the connector orientated as the manual shows. After fitting, clear codes, perform an ECU relearn if required, and take a road test to confirm normal knock correction.

Owners might notice symptoms like audible pinging under load, sluggish performance, poorer economy, or the MIL on. Don’t ignore it—continuing to drive with detonation risks piston and valve damage. A quick check under the bonnet and a scan can save a lot of grief and keep the Exiga quietly doing its family-hauling thing for many more kilometres.

• Where is the knock sensor on a 2014 Subaru Exiga?
  It’s bolted to the top side of the engine block under the intake manifold, roughly central. There’s typically one sensor, access is from above once intake ducting and covers are out of the way.
• What codes point to a bad knock sensor?
  Common DTCs include P0325 (circuit fault), P0327 (low input) and P0328 (high input). Always check wiring, connector fit, and mounting torque before condemning the sensor.
• Is it safe to drive with a faulty knock sensor?
  The ECU will usually pull timing, so the car may feel down on power. It’s best to sort it promptly—if the ECU can’t reliably detect knock, the engine could be exposed to detonation under load.