GoolRC Digital Air Fuel Ratio Gauge Kit 12V 2 in 1 Meter 52MM Narrowband Car Volmeter with O2 Oxygen Sensor Car Modification Acces White cover

Worked awesome for tuning my dr650. it is narrowband, not wideband so reading on the rich side is not as good...only goes down to about 11-12 AFR. So start lean 15+ and slowly richen each circuit to 12-14. I didn't even look at the instructions based on other reviews...follow the wiring as outlined in other review.

Works. Installed it on my carbureted ATV to get an idea on how it’s tuned and maybe dial it in some. Super cool. Shows AF Ratio as soon as the sensor warms up. LED colors for AF Ratio are deceiving. The higher grams of air per gram of gas are represented with red LEDs. Ie 18-19-20. So lean shows red LEDs. Close to Stoich are amber LEDs. Rich mixtures are green LEDs. Ie 10:1. I had one of these years ago on my Honda civic. It was an expensive Auto Meter and I’m pretty sure the LEDs were reversed. Red = Rich and Green = Lean. LED colors are correct. Remember now and I get the RED = Lean. Shooting Nitrous on my civic I wanted to be rich so seeing Green means good

Minus 1 star for missing instructions for wiring the sensor. It dos include instructions for wiring the gauge, though. Also annoying that it shows battery voltage for the first minute, before it switches to A/F ratio. I guess it does say "2 in 1... car voltmeter..." So I can't count that against them. Sensor wiring: Black -> green wire on gauge (sensor reading to gauge) Gray -> ground (sensor's ground) White -> ground (heater's ground) White -> +12V when ignition on (heater's +12V) (Notes regarding heater: A/F ratio sensors (aka O2 sensors) need to be hot enough to read accurately. The heater inside the sensor heats it up to operating temp. A vehicle's computer will switch the its O2 sensor heater on as needed, but you're not connecting this to the car's computer. So, you can connect it to ignition +12V. It is okay for the heater to stay on with the ignition.) Gauge wiring: Red -> +12V when ignition on Yellow (backlight)-> +12V when ignition on or +12V when instrument cluster lights on. Black -> ground Green -> sensor's black wire Make sure you install the sensor as far up the exhaust gas stream as you can (closer to engine better). If you install it too far back, things will give it inaccurate readings. For instance if you install it too close to the end of the exhaust, you will get lean readings (high A/F ratio number) because as the exhaust pulses, it sucks in some ambient air. I tried making a "sniffer" that inserts into the tailpipe and found I have to insert the sensor at least 18 inches into the pipe before I got what could be accurate readings compared to installing it into the exhaust downpipe after exhaust manifold.

Item had no instructions whatsoever, since I do this for a living I was able to figure out the wiring. I'm not so sure others would be able to. Once hooked up, the gauge makes some lights, and unfortunately after that it does nothing else it's supposed to. It reads nothing for air/fuel mixture... Until 2 seconds after you shut the motorcycle off, then it shows a mixture reading. The voltmeter, is the equivalent of somebody shouting random numbers at you and hoping to God that one of them might be the actual number you're looking for. You can see from my pictures that what reality is and what the voltmeter is reading are two vastly different things. Upon returning to the sellers ad in attempt to ask about possible calibration of the gauge, what and if there is a warranty and perhaps if I have missed something I was unable to find anyway to contact the seller. Although there are several places that indicate you must contact the seller for the information. For instance, under the warranty section, it's specifically states that you have to contact the seller. After 30 minutes of searching, I broke down and contacted Amazon. After another 30 minutes of talking to chatbots, I was finally graced with the opportunity to talk to a real person. The person did everything in their power to get me to just return it and buy another one. After asking nine times, I was given a phone number that may or may not be the sellers. Absolutely mind-boggling.

Verified to an oscilloscope this is a short band or narrow band O2 sensor 1volt range lean or rich. Is all you'll get from this. At first thought possibly just reading temperature so I hooked up the heater wires let warm up and simply put gas to it not flame and it appears to work as intended and described.

Instructions are horrible and 1/2 in Chinese. If you don't have mechanical experience of patients to figure it out it's not for you. Gauge looks nice. Wires are very small. The o2 sensor has extra heat wires. The ring on the back to hold it self was nice.

Products were as represented

Looks good haven't installed yet

It works

It is not working properly, and the readings are not stable even after tuning

This is a good way to monitor how the car is running. It lets you know how the engine is performing. I would recommend it.

The gauge stopped working after 5 min of operation, also the instructions on how to connect the o2 sensor wiring to the circuit is not available.

Tried so many ways to wire it. Doesnt read. Eventually goes to 20 on the gauge and stays their.