Where is the knock sensor located and How to remove and install on Mazda 3?

The location of the knock sensor is in the front side of the block and at the back of the runners of the intake manifold. The first step would be to take off the battery cover and unplug the cable in the negative battery terminal. The intake manifold should be removed next. You can then disconnect the electrical connector to the knock sensor followed by removing the bolt of the knock sensor and removing the knock sensor. To install it, repeat the steps of removing it and tighten the knock sensor bolt to the required tightness.

Genuine Mazda 3 Knock Sensor

Engine Knock Sensor

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5 Knock Sensors found

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Mazda 3 Knock Sensor Part Number: LF01-18-921
$43.75 MSRP: $58.35
You Save: $14.60 (26%)
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Product Specifications
- Other Name: Sensor, Knock
- Replaces: 1F20-18-921A, 1F20-18-921
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 2010-2013, 2004-2006 Mazda 3 | i, S, SP23 | 4 Cyl 2.0 L GAS, 4 Cyl 2.3 L GAS, 4 Cyl 2.5 L GAS
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Mazda 3 Knock Sensor Part Number: PE01-18-921
$62.38 MSRP: $83.18
You Save: $20.80 (26%)
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Product Specifications
- Other Name: Sensor, Knock
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 2012-2018 Mazda 3 | Grand Touring, i, i Grand Touring, I Sport, i SV, I Touring, Mazdaspeed, S, s Grand Touring, s Touring, Sport, Touring | 4 Cyl 2.0 L GAS, 4 Cyl 2.3 L GAS, 4 Cyl 2.5 L GAS
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Mazda 3 Knock Sensor Part Number: P31E-18-921
$93.71 MSRP: $124.98
You Save: $31.27 (26%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Sensor, Knock
- Replaces: P32E-18-921
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 2019-2024 Mazda 3 | 2.0, 2.5 Carbon Turbo, 2.5 S, 2.5 Turbo, 2.5 Turbo Premium Plus, Base, Carbon Edition, Preferred, Premium, Select, Select Sport | 4 Cyl 2.0 L GAS, 4 Cyl 2.5 L GAS
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Mazda 3 Knock Sensor Part Number: LF02-18-921
$95.44 MSRP: $127.28
You Save: $31.84 (26%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Sensor, Knock
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 2007-2013 Mazda 3 | i, Mazdaspeed, S | 4 Cyl 2.0 L GAS, 4 Cyl 2.3 L GAS
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Mazda 3 Knock Sensor Part Number: L807-18-921
$114.39 MSRP: $152.54
You Save: $38.15 (26%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Sensor, Knock
- Warranty: This genuine part is guaranteed by Mazda's factory warranty.
Fits the following Vehicles:
- 2007-2013 Mazda 3 | Mazdaspeed, S | 4 Cyl 2.3 L GAS

Mazda 3 Knock Sensor

The Mazda 3 Knock Sensor is an early alert mechanism in the car to warn the car owner of harmful knocking in the engine, and the system will detect the abnormal combustion immediately and inform the powertrain control module to correct it before it is damaged. The Knock Sensor is based on a piezoelectric core which converts the sharp vibrations of detonation into electrical impulses, supplying a control loop which adjusts ignition timing in minute steps. When knock sets in, timing is delayed to the point where it reduces the spikes in pressure and then slowly stepped forward again to ensure that the engine is brought to the point of optimum operation without going into the dangerous region. This continuous valving enables drivers to have maximum performance using lower octane fuel and enables Mazda engines to balance power with reliability in relation to changing altitude or temperature. The first generation applied a single sensor that initiated a blanket timing adjustment in the entire engine, but subsequent implementation in the more extensive Mazda range can target individual cylinders and, on turbo engines, can coordinate this with boost control to provide even finer protection. Although all the sensors in the family operate under an identical principle of vibration to voltage, more recent assemblies in newer Mazda 3 models provide a faster response and better resolution. All in all, the Knock Sensor maintains the smooth operation of the combustion engine, secures the internal components, enhances fuel efficiency and permits the engine to live longer, without the driver ever realizing that it is working quietly around the clock.

Looking for Knock Sensor with proven quality? Choose OEM Knock Sensor. Mazda designs and builds them to strict factory specs. Every piece goes through rigorous quality checks. You'll get parts that fit right and work like new. Shop our huge inventory of OEM Mazda 3 parts. Enjoy the highly competitive prices online. Our site is your one-stop shop. Each genuine 3 part includes a manufacturer's warranty. Buy with confidence. Our return policy is simple and hassle-free. In a rush? Choose expedited delivery at checkout. You'll love the streamlined experience from search to checkout to receiving your order.

Mazda 3 Knock Sensor Parts and Q&A

Knock Sensor
LF02-18-921
Q: Where is the knock sensor located and How to remove and install on Mazda 3?
A:
The location of the knock sensor is in the front side of the block and at the back of the runners of the intake manifold. The first step would be to take off the battery cover and unplug the cable in the negative battery terminal. The intake manifold should be removed next. You can then disconnect the electrical connector to the knock sensor followed by removing the bolt of the knock sensor and removing the knock sensor. To install it, repeat the steps of removing it and tighten the knock sensor bolt to the required tightness.