AEM(30-4110) UEGO Air/Fuel Ratio Gauge

Entirely outstanding in terms of price and performance. This much value for 150 dollars is amazing compared to what you got for your money 15-20 years ago. Back then you paid more and didn't even get a gauge let alone a good one with an easy install.The gauge is easy to read, responds quickly and looks pretty. It doesn't flicker or anything so I don't know why people complain about distracting flashing lights. The brightness seems just right for every situation so far and you don't notice it unless you glance over to the windshield pillar- maybe it's annoying with gauge cluster mounting or with internal LED lighting or something. Dunno. Everyone's car is different. But I had no problems in my NA miata, even in bright sunlight with the top down.Installation was straightforward and easy except for the firewall routing. If you have an easy passage through your firewall and 12v/GRND/signal wires already set aside, this is under a 5 minute install. I had the thing up and running in about 2 minutes... then 2 hours later I had it installed in my dashboard. The extra two hours was entirely devoted to firewall/dashboard cable routing. Getting the rectangular cable connectors fed through the firewall was annoying but that's the worst of it. With practice I could probably get it down to 15-20 minutes.The gauge feels a bit fliimsy compared to autometer (which feel like they're made from metal or something), but you won't ever touch it once installed, so this is a minor quibble.

Before I bought this gauge, I tried to save some money by purchasing a cheap eBay APSX wideband. That was a mistake, the wiring was cheap, the connector was junk, it didn't work right off the start, and was broken after a week.This gauge is phenomenal. The wiring is all thicker gauge (I think 18?) which was bigger than the cheap one I got.The sweeping LEDs work great and look very smooth while driving.The LED numbers are very easy to read and show up nicely under any lighting conditions.The ONLY complaint I have is that when you are off the throttle and the A/F ratio is 19 or so, it just reads "--" and I wish it would say 19. It's not an issue of any kind and it doesn't do it any other time than when you see coasting off the throttle.Overall this is a great gauge and I would absolutely reccomenend spending the extra 30$ to but this instead of the cheap eBay one.

It works and it preforms very well, it's very responsive to sudden changes. A lot of the instillation and preformance depends on the vehicle but the power wiring pigtail could be another foot longer and the sensor lead itself is plenty long for my installation.You will need to know basic wiring and have a second bung welded into your exhaust in the correct spot. The "P4" setting is terrible, do not buy it for this purpose. It's not emulated well at all actually just makes my miata (1994 1.8L) run deathly lean, almost like the stock ecu isn't reading the signal correctly (wiring was verified through factory wiring diagrams). I ended up buying a new narrowband and welding in the provided bung after already cutting into the wiring.The setting switch is deeply recessed into the device and the retention tab actually blocks access to it. The two wiring pigtail connections and placed too close and the cutout for them is not big enough, they both just barely fit in and you have to wiggle with it a little to even get both to get into place. It works as it is but it's not ideal.After a few months and one return/replacement later because of a faulty bosch sensor and some weird troubleshooting, it's had no issues since and I've placed about 2500 miles on it with quick readings, and no sun glare even with the top down and shining on it.Update 12/10: I have since moved to standalone and don’t need the narrowband emulation feature anymore. Unfortunately after 4000 miles the sensor again has died and reads full lean, it also fails the brake clean test miserably with no response even when soaked. Will be contacting seller for a potential replacement sensor.

AEM is a well known company in the car world, and makes high quality products. I purchased this gauge to monitor my AFR and log for open source tuning purposes. Installation was painless and took roughly 20 minutes since my downpipe already had a bellmouth o2 bung. I strongly recommended that you buy an add-a-circuit fuse kit (ASIN B01LFXA5UA) if you don't have any, it will make installation much easier so that the gauge can be powered by one of your car's powered circuits, like the radio. I had a few spares laying around, so I spliced this gauge and a boost gauge to one fuse kit without any problems. The kit also comes with several butt splices although one would suffice. The cables for the gauge are extremely long, so be aware that you must have adequate room to tuck them away. I paired this gauge with an AEM boost gauge (ASIN B001DX7KMY) and SMY Dual Gauge Cluster (ASIN B01M7MEKUS). The numbers are also very readable in the day time and stand out in the night, although the sweeping color band is a bit washed out during the day but still visible. No issues with this gauge and I'm very pleased! The AEM sticker that came in the box was a bit damaged, so I only gained +4 HP instead of the expected +5 HP.