My AFX wideband worked just like it should up until last week. The display is pegged at 16.00 and will not change. It is also hooked up to HP Tuners EIO and reads ~12.0 at idle and does change with throttle, but is not correct. I tried a free-air calibration and checked continuity between the O2 sensor connector and the controller connector. No effect so I replaced the NTK sensor and still no effect.

Does anyone have an idea of what's causing the problem? Could the controller have gone bad?

 

Start with confirming your HP Tuners VCM Scanner is using the correct values for the NGK AFX EIO. No, it can't change itself but everything at this point is process of elimination. Disconnect and reconnect all electrical source wiring for the NGK AFX and the connections leading into your HP Tuners EIO input.

Just turn the AFX on in free air rotate the **** til it reads CAL- and stick it in the exhaust and start tuning. When it see's exhaust it will accept your free air values and start sensing.

Now...

If you cannot calibrate the AFX or if the display shows “Sen#” (“#” is a trouble code number), you should:

1. Check if the sensor is attached
2. Check if the wiring harness is damaged
3. If steps 1. and 2. show no problems, replace the AFR sensor. It has reached its limit for useful life.
4. Contact NGK Spark Plugs (U.S.A.), Inc. for additional information on trouble codes
• If the display shows “Bat_,” the supply voltage is too low (below 11V).
• If the display shows “Bat¯,” the supply voltage is too high (above 28V).
• If the display reads “9.00,” the AFR is 9.00 or less
• If the display reads “16.00,” the AFR is 16.00 or more
•When using the AFX on modern fuel injected engines, you may experience
occasions where the controller display momentarily goes in to calibration mode,where the display will briefly read “Air_,” “Air¯,” or “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 the engine during deceleration.


You only have "60" warranty from purchase date for the NGK AFX wideband hadware.

To get NGK direct tech help...

Call 1-877-473-6767

or

Email: info@ngksparkplugs.com
Subject: AFX SUPPORT

 

Thanks for the reply. I have called NGK Tech Support before for an unrelated issue and they were helpful. I suspect the controller is the issue (which is odd since it is on a 3A fuse that is fine and the WB only has maybe 500 miles on it) and will follow-up with tech support tomorrow.

 

I had the display on my AFX go out, it had power, the analog outputs still put out voltage and the sensor would heat up, but no digits or anything on the display. I was wondering if anyone else had this problem? I owned it for 6 weeks (still in warranty) and I only started my truck about 6 times.