P0325 — Knock Sensor 1 Circuit Malfunction (Bank 1)

P0325 means the knock sensor on Bank 1 isn't reporting properly to the ECU. Usually it's a failed sensor or damaged wiring under the intake manifold.

Cost range: $100–$700. Severity: medium. Safe to drive? Yes, but the ECU will retard timing and you'll lose power and MPG until fixed.

Most common causes of P0325

1. Failed knock sensor — Common on Toyota and Nissan V6/V8 engines under the intake. ($100–$400)
2. Damaged knock sensor wiring — Sensor harness deteriorates with heat. ($50–$200)
3. Loose sensor mounting bolt — Specific torque required for proper signal. ($0–$20)

Symptoms drivers report with P0325

• Power loss
• Reduced MPG
• CEL