Home › P0325

P0325 Knock Sensor 1 Circuit Malfunction (Bank 1)

What it means

There's a problem with the knock sensor or its circuit. The knock sensor listens for engine pinging so the computer can retard timing.

Severity: Moderate

Can I drive it? Drivable, but power/economy may drop. Use the recommended fuel octane and avoid heavy loads.

Common causes (most likely first)

Faulty knock sensor
Damaged wiring/harness (common under intake manifold)
Corroded connector

Likely fixes

Inspect wiring
Replace knock sensor (and harness if damaged)

DIY parts cost

$20–$150

Approximate estimate

Shop repair cost

$150–$600

Approximate estimate, parts + labor

DIY difficulty

Moderate to Hard

Varies by vehicle

Cost ranges are rough, approximate U.S. estimates and vary widely by vehicle, region, and parts brand. Always confirm the diagnosis before buying parts.

Parts you may need

Knock sensorCheck price
Knock sensor harnessCheck price

Affiliate links are placeholders. Verify fitment for your year/make/model.