HKS AF KNOCK AMP 2/3 A/F Sensor (hks44999-AK022)

Regular price $265.50 USD Sale price $265.50 USD Regular price $295.00 USD
Sale 10.0% $29.50 USD (10.0%)
Special order - Ships in 8+ weeks
SKU: hks44999-AK022
Product Description

The HKS A/F knock monitor is an extremely valuable addition to any vehicle that has undergone extensive modifications. Indeed, for those who are likely to use the HKS F-Con Pro ECU then its use is virtually essential. The unit consists of a visual head unit that shows both knock and air/fuel ratio data. A remote-mounted separate signal amplifier is used to help keep the size of the head unit as compact as possible. The amp can be mounted anywhere in the vehicle out of sight. The knock (detonation) side of the unit picks up from the original sensor/s mounted to the vehicle. The sensitivity of original equipment sensors can vary from car to car and thus it is the tuner's decision to decide whether they are accurate enough for the purpose of monitoring or not. The air/fuel ratio side requires the use of an extremely sensitive wide-band Lambda sensor. HKS recommends the Japanese NTK sensor as it is one of the most accurate available. Unfortunately, these sensors are very expensive but at the moment we have not come across an equivalent alternative and as air/fuel ratio monitoring is taken very seriously we have no option but to continue with the NTK setup. The unit is extremely useful when used in conjunction with any F-Con Pro setup as not only is the factory knock detection system rendered inoperable but the F-Con Pro can also use the air/fuel ratio data supplied by the HKS knock monitor to self-learn and therefore map the fuel curve. This can save huge amounts of expensive mapping time and will go some way to offsetting the cost of the knock monitor and wide-band NTK sensor.


  • Special Order
  • Pictures may differ in the actual product


  • Universal


  • A/F Knock Amplifier
  • Use with HKS F-CON Pro ECUs
  • Wideband Lambda-Style Sensor
  • High-Quality Wiring
  • Length: 120
  • Width: 35
  • Height: 170

To provide faster delivery and turn around time; Kami Speed ships products out from different warehouses throughout the United States. Usually averaging 1-4 business days for processing prior to shipping.

Depending on the package, we ship using different carriers according to the item's location, content, and size.

Freight truck & international items, will require up to 7 business days to ship due to size and logistics.

All orders made after 3:00pm ET will be shipped or processed the next business day.

Unless otherwise noted as "In Stock" or exact ETA. Special Order items have an ETA of 5+ weeks.

Orders over $500 will ship insured and over $1,000 with signature and insurance in order to guarantee delivery. Orders over $1000 may not be able to ship to a different address not listed as the billing address or confirm payment address from the form of payment used. Orders with suite numbers, different billing, or apartment numbers will require signature if valued over $100.

All international orders outside of the USA are subject to duties and taxes fees per your countries jurisdiction and determined by customs.
Kami Speed serves the right to ship using an alternative method if we see it fit, in order to expedite shipping and reduce your rate depending on product value.

Processing and logistics on in stock international orders can take up to 7 business days to process & ship.

In stock, non special order items can be returned within 30 days of the product arriving to your house or place of work.
Returns will NOT be accepted on Clearance Items, Final Sales, Special Orders, Opened, Installed, Incomplete, or Otherwise Used Products. In order to initiate a return, an RMA number must be requested and approved via e-mail. All returns will be subject to a 20% restocking fee minus complete shipping cost (roundtrip).

Any processed orders that have not shipped will incur a 6% cancelation refund fee unless the product was not available to ship within a timely manner. No fee will be incurred if used as store credit.

For complete details on our return policy, please see our Help and FAQ link under HELPFUL INFO.

WARNING: Operating, servicing and maintaining a passenger vehicle or off-highway motor vehicle can expose you to chemicals including engine exhaust, carbon monoxide, phthalates, and lead, which are known to the State of California to cause cancer and birth defects or other reproductive harm. To minimize exposure, avoid breathing exhaust, do not idle the engine except as necessary, service your vehicle in a well-ventilated area and wear gloves or wash your hands frequently when servicing your vehicle. For more information go to

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