Parts for your 2004 Toyota Camry-Knock sensor

2004 Toyota Camry knock sensor: purpose, fitment, and service tips

Yes, the 2004 Toyota Camry is fitted with knock-sensor hardware. Technical sources including the Toyota Camry 2002–2006 Repair Manual, the Toyota Electronic Parts Catalogue, and common diagnostic references list a knock sensor for the 2.4L 2AZ‑FE four-cylinder (one sensor on the block) and two knock sensors for the V6 variants (1MZ‑FE/3MZ‑FE, one per bank beneath the intake manifold). These same sources note diagnostic trouble codes P0325 and P0330 for this model year, further confirming fitment.

On this Camry, the knock sensor listens for high-frequency vibrations caused by detonation (knock) and feeds a signal to the engine ECU. The ECU then trims ignition timing to protect the engine and keep performance and fuel economy tidy, even on everyday 91 RON petrol found across Australia and New Zealand. Without a healthy sensor, the ECU often plays it safe with retarded timing, which feels flat and drinks more fuel.

There’s no set replacement interval, the sensor is a “fit and forget” part until a fault crops up. Still, it’s smart to keep an eye on the wiring and connector during routine servicing, especially at higher kilometres. Tell-tales of a drama include a check engine light, pinging under load, doughy performance, or scan-tool codes P0325 (Bank 1) or P0330 (Bank 2 on V6).

• 2AZ‑FE 4‑cyl: a single sensor is mounted on the block under the intake side. Access generally means removing the intake manifold, plan for fresh manifold gaskets.
• V6 (1MZ‑FE/3MZ‑FE): two sensors sit in the valley under the intake manifold. If one fails, many techs replace both sensors and the sub‑harness while the manifold’s off.

Replacement tips that align with Toyota workshop guidance: use a quality OEM‑spec sensor, clean the seating surface on the block, and tighten to around 20 N·m with a torque wrench (confirm exact spec in the service manual). Don’t use sealant or Teflon on the threads, and route the loom exactly as per factory to avoid false knock from vibration. After installation, clear codes and let the ECU relearn with a normal drive cycle.

Technical references consulted: Toyota Camry 2002–2006 Repair Manual (engine control diagnostics and component locations), Toyota Electronic Parts Catalogue (2004 Camry listings for knock sensor and sub‑harness), and Australian/New Zealand service literature noting DTCs P0325/P0330 on 2AZ‑FE, 1MZ‑FE, and 3MZ‑FE engines.

Does a 2004 Camry have one or two knock sensors?

The 2.4L 2AZ‑FE four‑cylinder uses one knock sensor on the intake side of the block. V6 models (1MZ‑FE/3MZ‑FE) use two sensors, one per bank, located under the intake manifold in the engine valley.

Can the car be driven with a faulty knock sensor?

It’ll usually run in a “safe” mode with retarded timing, but it’ll feel sluggish and use more fuel. It’s not wise to leave it that way—get the fault diagnosed and sorted to protect the engine and restore proper performance.

What torque spec and extras are needed when replacing it?

Typical torque is about 20 N·m, but always check the exact figure in the workshop manual. On V6 cars, consider new intake gaskets and the knock sensor sub‑harness while you’re in there. Keep the sensor face and block surface clean, and don’t apply thread sealant.