Wideband Air/Fuel and Boost in One Gauge!

Brand new in the box  - 100% AEM product - Made in USA

The Wideband FAILSAFE Gauge provides the ability to accurately tune AFR, while actively protecting your engine by constantly monitoring AFR curves and activating a user-defined failsafe strategy if it runs lean.

The Wideband FAILSAFE Gauge is a Universal Exhaust Gas Oxygen (UEGO—“you-way-go”) controller with an internal boost sensor, an internal data logger and a full color Organic Light Emitting Diode (OLED) display. It includes technology to activate a failsafe strategy in the event AFR falls outside of a user-defined operating window. If the AFR falls outside of the set operating window, the Wideband FAILSAFE Gauge triggers a user defined output function that can save an engine from catastrophic damage.


The 52mm (2-1/16”) Wideband FAILSAFE Gauge includes a Boch 4.9 LSU AFR wideband sensor for monitoring and feedback of AFR and an on-board boost sensor to read vacuum or boost pressures up to 29 PSIG. Both boost and AFR can be displayed in real time on the gauge’s face using the full color OLED screen and 24 three-color sweeping LEDs. The gauge includes a low side output for triggering a failsafe strategy in the event AFR falls outside of the operating window (example strategies below), and an RPM input to log RPM for tuning purposes.


Kit comes with 6 different faceplates and black and silver bezels.
Black and White AFR in sweeping LEDs
Black and White Vacuum/Boost in sweeping LEDs
Black Vacuum only in sweeping LEDs
Black Lambda in sweeping LEDs


Displays both boost or vacuum and AFR or Lambda simultaneously on the same gauge
No free air calibration required – ever
Internal boost sensor
Boch Wideband UEGO sensor and weld-in bung included
On-Board 3+ hour Datalogging capability at 20hz per parameter
Full color Organic Light Emitting Diode (OLED) Display in center, user selectable feature (boost/vacuum or AFR)
24 three-color sweeping LEDs, user selectable feature (boost/vacuum or AFR)
Intuitive set up software
Interchangeable faceplates and bezels (see options, above)
Data analysis using AEMdata software


AEMnet compatible (CAN 2.0)
Differential AFR analog output
Differential boost analog output
Configurable RPM input for logging
One low-side driver output (Ground with 1.5 amp max draw)
Positive-lock connectors
Tunable PC-based software with USB connectivity
Time based reset for outputs

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AEM Digital Failsafe AFR wideband AIR / FUEL RATIO and boost gauge #30-4900

  • Product Code: 30-4900
  • Availability: In Stock
  • £265.99

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