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Lexus Rx300 Ignition Knock (Detonation) Sensor Kits

Lexus Rx300 Ignition knock (detonation) sensor kits

Starting at $226.95, AutoBuffy stocks 1 ignition knock (detonation) sensor kits from Standard Ignition. The knock sensor listens for abnormal combustion knock caused by pre-detonation and signals the ECU to retard ignition timing, protecting the engine. A failed sensor triggers a check engine light and leaves the engine unprotected against damaging detonation.

Signs your Lexus Rx300 needs a new ignition knock sensor kit

  • Check engine light on with stored codes P0325, P0326, P0327, P0328, P0332, or P0333
  • Noticeable engine knock or pinging sound, especially under load or acceleration
  • Reduced power and sluggish acceleration as the ECU holds ignition timing in a retarded failsafe mode
  • Decreased fuel economy because retarded timing burns fuel less efficiently
  • Hesitation or stumbling during hard acceleration or when climbing grades
  • Failed emissions test due to an active knock sensor fault code affecting engine management

Which ignition knock sensor kit should you buy for your Lexus Rx300?

Knock sensor kits vary by sensor construction (flat response vs. resonant type) and whether they include the wiring harness connector pigtail. Matching the correct sensor type and connector style to your Lexus Rx300 is critical, as an incorrect type will set fault codes even if it physically fits. OE-quality sensors with included harness connectors are the safest replacement choice.

OE Replacement Kit (sensor + harness connector)
Best for
Most owners wanting a direct, code-free fix
What you get
Exact-fit sensor and pre-wired pigtail connector that replaces the factory unit without splicing
Sensor Only (no harness)
Best for
Vehicles with an undamaged, reusable factory connector pigtail
What you get
Drop-in replacement sensor at lower cost; requires the original harness to be in good condition
Flat Response (broadband) Sensor
Best for
Engines that use a broadband knock sensor per OE design
What you get
Detects a wide frequency range; required when the OEM spec calls for this type — not interchangeable with resonant
Resonant (tuned frequency) Sensor
Best for
Engines originally equipped with a resonant-type knock sensor
What you get
Tuned to a specific vibration frequency matching the engine's knock signature; must match OE type exactly

Ignition knock (detonation) sensor kits brands we stock for your Lexus Rx300

Standard Ignition
1 option · from $226.95

Replacing an ignition knock sensor kit on a Lexus Rx300

Moderate⏱ 1–3 hoursSocket set with extensions (metric and standard)Torque wrenchWire terminal pick or connector release toolPenetrating oil (for corroded sensor threads)OBD-II scan tool (to clear fault codes after replacement)

Locate the knock sensor on the engine block or beneath the intake manifold, disconnect the harness connector, and remove the sensor using the appropriate socket. Thread the new sensor in by hand first to avoid cross-threading, then tighten to the manufacturer's specified torque range — over-tightening or under-tightening will affect sensor accuracy and can cause new codes. Reconnect the harness or new pigtail connector, clear stored fault codes with a scan tool, and verify the check engine light does not return after a short test drive.

Frequently asked questions

How much does it cost to replace ignition knock sensor kits on a Lexus Rx300?
Parts start at $226.95 for a knock sensor kit at AutoBuffy. Professional labor typically adds one to two hours of shop time depending on sensor location. On many engines the sensor is buried under the intake manifold, which significantly increases labor cost. Doing it yourself with basic tools can keep the total expense to just the part cost.
Can I drive my Lexus Rx300 with a bad knock sensor?
You can drive short distances, but it is not advisable for long or hard driving. A failed knock sensor leaves the ECU unable to detect detonation, so it either retards timing permanently — reducing power and economy — or, in some calibrations, allows knock to go undetected and cause serious internal engine damage over time.
Will a bad knock sensor always trigger a check engine light on a Lexus Rx300?
In most cases, yes. The ECU continuously monitors the knock sensor circuit, and an open circuit, short, or signal out of range will store a fault code and illuminate the check engine light. However, a sensor that has degraded sensitivity rather than failed completely may not always set a code immediately, making symptoms the first clue.
Do I need to replace the wiring harness connector along with the knock sensor on my Lexus Rx300?
Not always, but it is strongly recommended when the existing connector shows corrosion, brittle insulation, or damaged terminals. A faulty connector causes the same fault codes as a bad sensor. Kits that include a pre-wired pigtail connector make the repair more reliable and eliminate connector condition as a variable when diagnosing.
How difficult is it to replace a knock sensor on a Lexus Rx300?
Difficulty varies widely by engine layout. On some engines the sensor is accessible from above with basic hand tools and takes under an hour. On others it sits beneath the intake manifold, requiring significant disassembly and making it a moderate to advanced job. Check sensor location on your specific Lexus Rx300 before deciding whether to DIY or use a shop.
What happens if I install the wrong type of knock sensor on my Lexus Rx300?
Installing a resonant sensor where a broadband (flat response) type is required — or vice versa — will result in persistent fault codes, incorrect timing adjustments, and potential engine damage. The ECU expects a specific signal pattern. Always verify OE sensor type (flat response vs. resonant) and connector style before purchasing a replacement for your Lexus Rx300.

Shop ignition knock (detonation) sensor kits by year for the Lexus Rx300

2003200220012000

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Ignition knock (detonation) sensor kits for other Lexus models

Lexus SC300Lexus ES300Lexus IS300