FAQs - AFX

Q: There are many wideband systems on the market today. What makes NGK's better than the competitors'?

A: NGK has long been the world leader in exhaust gas sensor technology with its NTK brand oxygen sensors. Who better to create a wideband controller than the company who is the authority on wideband sensors? The benefit of the AFX comes from the many years and millions of dollars of NGK sensor research and development. Our system utilizes that technology.
Don't be misled by competitors claims of knowing the ins and outs of wideband sensor technology, or even some who simply manipulate narrow band sensor signals and call that air-fuel ratio monitoring. The AFX is a true wideband system that is rugged, versatile, and simple to use. It eliminates the guesswork from carburetor and fuel injection tuning and can save you valuable time and money.
The AFX is an affordable, easy to use system that is packed with many years of NGK sensor technology.

Q: What is included in the kit?

A: The AFX comes with everything you need to start tuning:
• Digital display controller
• 13' wiring harness
• Wideband sensor
• Exhaust boss & plug
• Comprehensive air-fuel ratio tuning manual
Replacement parts are available through the selected AFX distributors.

Q: What is the range of measurement for the AFX?

A: The AFX has a range of measurement of 9.00:1 to 16.00:1 for gasoline. This range equates to 0.62 to 1.10 Lambda. It is a precision tool that is accurate within 0.1 AFR.

Q: Is the AFX compatible with leaded fuel?

A: Yes. The AFX welcomes tuning using leaded race fuels. Note however that the sensor deteriorates faster with leaded fuels than with unleaded fuels. The AFX's proprietary calibration procedure helps extend the sensor's usable life and maintain accuracy throughout that lifetime.

Q: How long of a life can I expect from the sensor?

A: The AFX has been designed to extend the AFR sensors' life as long as possible. However, since sensor life depends on sensor operating conditions, it impossible to predict sensor life without knowing the conditions under which the AFR sensor was used. Therefore, the AFR sensor should be considered an expendable part; a cost of tuning, just like gasoline and your time. Some tuners will never kill a sensor. Some tuners will kill two sensors a race season. You may use the AFX as a constant AFR monitoring tool, but keep in mind that this will consume the sensor faster. If you are not using the sensor to tune the engine, we generally recommend you take it out. It may be a good idea to keep a backup sensor on hand if you tune constantly or if you tune at the track.

Q: Is the AFX compatible with fuels other than gasoline?

A: Yes. The AFX will work with commonly used race fuels like methanol. The display will simply show AFR on a gasoline scale (using 14.57:1 as stoichiometry) even though the fuel used may have different properties (stoichiometry for methanol is approximately 6.5:1). As long as you understand this, interpreting the values should be easy.
The same principle applies to other fuels such as ethanol, propane, CNG, LPG, etc. The display will simply read on a gasoline scale.
Also keep in mind that the properties of fuels like methanol may make it easier for thermal shock to occur to the sensor, possibly shortening its life. Please use care when deciding sensor mounting location.

Q: My exhaust configuration makes it difficult for me to follow the sensor mounting guidelines listed in the manual. Will the system still work?

A: Some exhaust configurations may make it difficult to meet each of the recommendations listed in the manual exactly, and some compromise in mounting may be required. The sensor does not necessarily have to precisely meet every mounting guideline listed to operate, but please understand that the better you conform to these rules, the longer the sensor will last and the more accurate the results will be. If you are unsure of your sensor mounting location, contact NGK for help.
Sensor Mounting guidelines are listed in the AFX Tuning Manual.

Q: During driving, my display sometimes jumps into calibration mode and reads "Air_", "Air¯", or "CAL-." Is the unit malfunctioning?

A: No, this is normal for some vehicles. When using the AFX on modern fuel injected engines, you may experience occasions where the controller display momentarily goes into calibration mode, where the display will briefly read "CAL-" during deceleration or upon releasing the throttle. This is normal operation and is caused by the fuel injection system cutting off fuel delivery to he engine during deceleration.

Q: Does the AFX have analog output capability?

A: Yes, the AFX has a 0 ~ 5V, linear analog output for AFR that can be used as an input to an engine controller or data acquisition system. The analog output signal wire is yellow and is attached to terminal position 3 of the connector that plugs into the controller. The analog output ground wire is brown and is attached to terminal position 4 of the same connector. The output wires are each 12" long and are hidden inside the mesh sleeve. To access the wires, gently pull them out of the sleeve. An output of 0V means 9.00:1 AFR and an output of 5V means 16.00:1 AFR (see below diagram). When the sensor is in air, the analog output will be pinned at 5V (since the AFR of air is infinity).

Mathematically: AFR = (1.4 x Output Voltage) + 9.

To see a graph of the analog output, click here AFX_Linear_Output_Chart

Q: What is the warranty on the AFX?

A: NGK Spark Plugs (U.S.A.), Inc. warrants that the products, which it sells to the Distributor, seller, reseller, or customer, shall be free from defects in workmanship and materials within a period of sixty (60) days from the delivery thereof to the aforementioned parties. This does not apply to products that have been modified, altered, abused, damaged during transit, or subjected to conditions in excess of their intended environment. Due to the nature of the product, there is no warranty on AFR sensor life.
NGK Spark Plugs (U.S.A.), Inc. shall not be liable for any economic damages or losses resulting from the improper use of its products.
This warranty is valid only in the U.S.A.

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