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AEM UEGO Failsafe Wideband AFR/Boost Gauge ( Part Number:AEM 30-4900)

AEM UEGO Failsafe Wideband AFR/Boost Gauge - Universal

MODEL # AEM 30-4900
Manufacturer Part # 30-4900


MSRP: $445.80

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RallySport Direct is proud to carry the AEM FAILSAFE Wideband AFR Gauge. This is a great way to safely and accurately monitor your AFR readings to provide insurance for your engine and to make sure your tune is always within the strike zone.

Here are the features:

  • This is a universal exhaust gas oxygen controller
  • Designed with an internal boost sensor, internal data logger, and a full-color organic light emitting diode (OLED) display
  • Includes technology to activate a failsafe strategy in the event that the AFR fails outside of a user-defined setting, will trigger a user-defined output function that can save the engine from catastrophic damage
  • The FAILSAFE function will continue to monitor the AFR and boost and vacuum to make sure that the AFR does not fall out of the defined operating window at a given boost or vacuum level
  • Guage will trigger a low side output if it detects an AFR reading that is out of range
  • Includes software to configure the low side output and create a user-adjustable time delay strategy to prevent false alarms
  • Contains an onboard for logging over 3 hours of data recording (20Hz per parameter) of AFR, RPM, boost, alarm, and others. Data logs can be downloaded for viewing in the new AEMdata software

More details:

  • 52mm gauge size
  • Includes Bosch 4.2LSU AFR wideband sensor for monitoring and feedback of AFR 
  • Includes onboard boost sensor to read vacuum or boost sensor up to 29 PSIG
  • 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
  • Includes a variety of gauge faces for user preference
  • Includes all of the wiring making this gauge ready for the installation



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Brand: AEM
Gauge Range Boost: -29inHG - 29.4psi (-1bar - 2bar)

Mfgr. Warranty: 1 Year
Condition: New Product
Return Policy:

RallySport Guarantee - 30 Days

Items that are covered under the RallySport Guarantee offer a 30 day no questions asked return policy.

RallySport Guarantee items may be returned within 30 days of the original invoice date and must include all the original parts and contents for a refund.

The RallySport Guarantee does not apply to products that have been modified, damaged, misused or abused. All returns require an RMA (Return Merchandise Authorization) Number, and freight charges are strictly non-refundable. For more information regarding our freight refund policy, please refer to our return policy page found HERE.



This product has no user uploaded media. You can upload your photo or video of your install by posting a review. Reviews:
Verified Purchase

Great Gauge
JCL 5 months ago
Tuner recommended I purchase this gauge, it is great. It has the capability to keep track of rpm, wideband and boost all in one. Worth every penny.
Verified Purchase

Two gauges in one...and it'll save your motor.
otto51722705 4 years ago
This gauge has saved my motor on at least three occasions and really is the perfect solution for those looking for a boost gauge AND an AFR gauge. My only complaints are that the installation/setup instructions are pretty thin (a good tuner/calibrator is needed to take full advantage of the gauge features) and the boost gauge is limited to 30psi. I wish it was much higher.

  • Q: Vacuum Hose Length  jdkluck 7 months ago


    How long is the vacum hose that is coming out the back of the AEM 30-4900 UEGO Failsafe Wideband gauge? I was just wondering how long it is to see how far it will get into the dash before you would have another hose hooked up to it. So in case you had to pull the gauge out you could disconnect the harness but was not sure how you would disconnect the vacuum hose if it was a longer connection before the fitting adapter. Thanks

    • A: The hose that comes out of gauge is only a few inches long. Access to the line would be very easy if needed.

      Jared A. 7 months ago
  • Q: Water/meth injection failsafe?  bseymour0269724172 8 months ago


    I was wondering if this was strictly an AFR failsafe or if it can double as a water/meth failsafe as the failure of the water/meth system would cause a drastic change in the AFR.

    • A: It can be doubled with the meth injection failsafe but you will have to wire and program it yourself.

      Tyler A. 8 months ago
  • Q: Bung  06stidd 3 years ago


    Can this go in the bung on the up pipe?

    • A: You will want to connect this to the bung on your downpipe, if you have the extra 02 bung. If you dont have one a exhaust shop should be able to create something custom for you.

      Trevor C. 3 years ago
  • Q: Gauge Dimming   organiclad3527444 3 years ago


    Can this be wired to dim with the stock gauges and interior? The description makes no mention of dimming of any sort, is it possible to dim it otherwise?

    • A: The gauge does have a dimmer wire which would be Pin 10 Gray *OPTIONAL* Gauge backlighting; connect to instrument lighting.

      Nick S. 3 years ago
  • Q: Single Pods  Shibikku 4 years ago


    Which single or mounted pod gives the AEM UEGO Failsafe best fitment? thanks!

    • A: This gauge will fit in almost any 52mm pod and it does not necessarily fit in one better than another.

      Zach G. 4 years ago
Universal Product
This item is non application specific.
Please verify compatibility before purchase. May require some modification for proper installation.