AEM afr gauge problems and most possible solution 

You guys need to realize either the the o2 location, o2 sensor it’s self or the gauge is faulty. You have to use the process of elimination.

Thank you for sharing this video, simple and shows exactly how it functions when working properly.

Good vid and answers the mail on AFR issues.

Great video Just wondering, you ran it to cycle when the engine was cold , and it started at 14.7 and then leaned out ( showing dashes). Did this mean that your sensor was good or bad?

Mine works most of the time just fine. But sometimes the gremlins cause 3 different types of weirdness. First, it will sometimes just stay at 7.5, which is the initial reading it gives for the first 5 or 10 seconds after starting. The second gremlin is where it will seemingly choose a random number and stay there for a few minutes. Third, is where it will oscillate wildly from lean to rich and back for a few minutes. This stuff scared me, so when it did the third behavior, I hooked up my laptop with the megasquirt software, and watched the little ball travel around the afr graph. The ball behaved normally, so that set my mind at ease. But the damn gauge is annoying when it misbehaves. I double checked the ground, and it's solidly attached to the original ecu firewall attachment point (no paint to mess with the signal).

Great vid super helpful!

The sensor will keep itself clean, via its heater, if it is always on, while the EGT is hot enough to cause carbon deposits to stick to it. i.e. the carbon will not stick to the sensor element, if the element is hotter than the EGT. That's, partly, why the sensor temp is set to 1450°F. So, in a prefect world, the sensor's heater is turned on right after start-up. Which is exactly what OEM ECU's that have WBs do :) Under those conditions, the WB sensors can last a long time. This is an electro-chemical sensor. So, exposing it to chemicals that it is not designed for is a bad thing

when I have the o2 sensor wire sensor plugged in and put the car in the on position and try to let it read lean, it just goes rich to 10 and stays there. what could be the cause of that?

hello mine was reading fine , had the engine out a few weeks ago , did some mods and put everything together today and started it , at first it started reading really high like 19-21.. first i tought there is a problem with the car but the funny thing is its still reading when the car is off with ignition on it gets up to 24 , is there something wrong with it ? greetings from austria 🙋🏻‍♂️

weird question is it bad to have the gauge wired without the OE sensor hocked up?

If you have issues with the gauge running 14.6/14.7 constantly it is still a senor issue not a gauge issue. Noticed a few people asking this question. I took from this video when he said stuck on 14.7 my gauge was my issue but it turned out it wasn't. Was just another faulty sensor failing. Hope it helps 👌

Hey love the video my sensor leaned out but then once started it really won’t move from 14.7 no matter how much gas I give it unless I turn car off then once off for a sec it leans with dashes

Just bought a new Bosch O2 sensor plug it all in start the car and it goes through its heat cycle and just stays on heat cycle. What do ya think, bad sensor?

I could use a little help y’all I have a 79 sbc 350 and the gauge was working fine and reading good then turned the car off and turned back on and now when car is started it is just the 3 dashes and red led is all the way but when I rev to about 2 k it reads around the 15 mark did my gauge instantly go bad? Tried messing with the a/f screws on the carb and still reads nothing

Hi from Australia, my gauge is all wired up and has power. I can select mode and cycle through and select. But when I turn the engine on, it doesn't have any of the startup as shown in your video. I have my sensor plugged into where my stock narrowband sensor would be. Any ideas? The supplied instructions say you can use the bung supplied in connection with your existing 02 bung, and either weld or use a special P/N to clamp it. Any ideas? Thanks.

After watching it I believe it might be the gauge I turn the ignition on and I can select through the modes but the numbers do not come up or stay on with vehicle on or off

This is almost always the result of a fractured sensor element. Which is almost always the result of starting an engine on a hot sensor. Letting the CERAMIC WB element "warm up" to 1200F/650C. And, then, blasting it with cold start-up exhaust, causes tiny fractures in the ceramic element. Eventually, they grow, like cracks in a windshield; and, either hit something vital. Or, they just start leaking in air. And, screw up the readings. Starting like that is, basically, like playing Russian roulette with your WB sensor. Some day, the WB manufacturers will decide to mention this in the directions.

Good and useful information

I bought an Auto Meter AFR WB gauge kit on Amazon. It constantly malfunctioned. I had it around a week or so when I gave up and returned it to Amazon and got a full refund. If I had bout it on the Auto Meter web sight I would be stuck with it. Currently I want to buy a dependable AFR gauge kit but that appears to be impossible. If the O2 sensors were manufactured to the same specs as automotive specs the O2 sensors should last longer , maybe?. The next one I buy will be powered with a normally open oil pressure switch in the power supply circuit ground side so the gauge will only be powered up when the engine is running and off when the engine is not running. Maybe this will help extend the life of these short life O2 sensors? Maybe

Any idea why my wideband. When turned on my truck. It reads 22.4 When I accelerate it reached 7.4 and when I let go back to 22.4

What happens when all the tests work but it leans fully out (carbed engine)

What does it mean when you get a single dash?

Hello mine does basically the same thing but after the 14.7. It gets stuck on 20.00 and flashes thanks jeff

What if my guage all of sudden doesn’t turn on at all? And yes my obd2 is working

This helped me out

When I turn my car on the gauge leans out and I get 3 dashes . It’s def gotta be a damaged sensor

so my guege is around 14 and then after some time it goes in red

what wire did you hook up to ignition? mine only said power, ground serial, and 0-5 volt output and I hooked mine up and nothing comes on

Ever seen one read normal then randomly read full lean for a bit then go back normal?

Can the sensor be mounted ag greater than 10 - 18 degrees? I mounted mine around 45 degrees... the instructions say “at least” ... more is better, n0?

what is the best one to buy just rebuild my engine 5.7 1990 k5 blazer i got edelbrock carb on there i already have headers so the hole is there for the 02 sensor i converted it from tbi to carb

My gauge is stuck on 14.6/14.7 it never changes from these. Not sure if it’s an o2 sensor or gauge. I also have codes for my driver front side o2 being stuck lean

nice video my gauge is reading 14A after a rebuild i rev the motor and the gauge stay stuck on 14A any way u can point me in the right direction is my first time with the AEM i always got good luck with PLX

My aem afr gauge keeps restarting. It wont stay on for more than a minute. Aem told me it was due to a bad sensor and they did send me a new one after I went through their troubleshooting steps of ensuring a good ground directly to the battery as well as connecting the gauge directly to the bateries positive, both did not solve the problem. Even with the new sensor the problem persists. Any ideas? I'm gonna get ahold of them tomorrow but thought i'd get your opinion.

Ok so I hooked everything up I did the gauge test and then the o2 sensor test.. they do as they should.. however when I start the car it does it's same cycle thing the digits then the POO then 14.7 but then it lean's itself out ?? I've also seen it it jump a few times went to 10.1 then back to ---... Any help would be greatly appreciated..

SIR, WHEN THE DIGIT ONE IS NOT LIGHTED COMPLETELY AND ONLY SHOWS ONE STRIPE OR VERTICAL HYPHEN LIGHTED WHAT IS THE PROBLEM WITH IT ????? IT IS MY ISSUE, THAT THE DIGIT ONE ONLY SHOWS THE HALF OF THE LIGHT TO SHOW IT LIGHTED ... WHAT DOES IT IMPLIES ???? IS THE MAIN MECHANISM OF READING WELL OR IS FAULTY ?? OR IS JUST THE BEAM RELATED TO THE LIGHT TO LIGHT THE DIGIT ONE ?????

Out of curiosity. My wideband worked just fine last time I drove it. Got in my car today. Immediately was on dashes. Would let off and go really rich then lean out again on throttle. My car is running at 14.7 via this app I have on my phone. But it’s still annoying my wideband isn’t functioning properly? Sensor? Faulty gauge? Literally just got this sensor a couple weeks ago

Hey man i just installed my afr gauge. im was positive i was running rich bc the amount of fuel fumes. When i started it my gauge did all the right stuff. ran for a little bit. stayed at 14.3 for a bit then started fluctuating between 10-15 really quickly. Do you know what it could be?

hey man so my gauge keeps pegging at 8.6 replaced the sensor with 4 different brand new serial matching sensors is it possible the gauge is bad.? it heats to 12 afr then starts the gauge at 12 and cycles down to 8 afr and stays pegged this is a brand new gauge talk about frustrated!

please help my afr gauge was completely fine and accurate my exhaust hit a steel plate real hard, hard enough to yank the whole exhaust past my bumper about 5-6" right away after the exhaust hit the plate the afr read 18.0 - 17.0 (i was light on the throttle) i fixed the exhaust, no leaks, there was still slack on the o2 harness wires for the afr gauge so i know the wire wasnt yanked. i recalibrated the afr o2 sensor and ever since then the gauge reads 14.7 on cold start, once the engine warms at idle the afr gauge shows 18.0 - 16.0 and it jumps between that range could be just the o2 sensor needs replacing from the exhaust being hit?

My gauge reads ... and never reads a number. I replaced the sensor and wire going to the sensor and still doesn't read never has read anything from brand new.. help... lol

I try the sniff test and doesnt work at'll. Stay ---. And i disconnect the o2 sensor and stay at 14.7. So might be the o2 sensor.

good morning mine remains fixed with three tachettes

My gauge keeps showing 3 dashes even though when the car is on and while driving as well. I replaced the o2 sensor but still no luck. Do you have any tips on what might cause it?

Mine reads 14.8 constant even with a brand new sensor

So I ran into a little problem, I installed a boost gauge but then when I started the car I gave it a little rev. After that my o2 sensor clicked then shut off and now it won’t turn back on

First 2 tests pass but when I turn on my car it stays all the way lean what does that mean? I need new o2?

Have you ever had a problem with the sensor itself, like the sensor not working after the motor is heat cycled?

I think my gauge is bad now watching your video because it stays at 14 every time I start it. Does AEM replace it under some warranty?

Hi ! my ARF X series probe has been malfunctioning for a week. When I turn it on the heating phase goes well, then the display is immediately at maximum with 4 red lines Sometimes when I decelerate there are very fast values ​​which are displayed for ½ second then the display returns to maximum with the 4 red lines. Bad contact and vibrations of the exhaust line or faulty probe? I tried the functions, only O2 mode seems to show variable information but I don't know if it's consistent. If I unplug the probe the display warns me, so I think it's not a connection problem, but I'm not sure.

What happens if I have the sensor everything connected and I start the car and it just leans out 17.1 to 18. Or 3 dashes I changed the sensor

so why did yours randomly shut off? mine did the same thing and will not come back on???

So what if i do all the test and my guage is working properly and I start the car and it reads around 13.2 ? Is that my o2 sensor ?

I barely put my O2 sensor in and my truck was at idle the other sudden went to the three lines but on my truck it has the two front oxygen sensors then on the back of the driver oxygen sensor there's another bung and that's where we screwed in my O2 sensor you don't think it's not getting a good reading

My guage says SENS.. changed the sensor and guage doesn't read anything but if I disconnect it it says SENS again

Mine does not read on idle New sensor as well cause I thought that would be it nope still idle 3 dash’s yes it used to work fine

Please help! My sensor seems to work fine until it heats up and it slowly moves lean and then I get the 3 dashes. Not sure what to do!

Mine will work then not work and work again then not work. So I'm assuming my 02 is bad

My wideband works properly for about 30 seconds then it starts reading more and more lean until its just pegged lean and won't respond

Thanks 💪💪

Anyone knows why mine says bAtt

Do I need a new o2 sensor if my aem guage is staying leaned out the whole time while driving, parked, hot, or cold? It worked fine for years until a couple weeks ago

Mine cycles through and immediately after it cycles through it goes straight to the 3 dashes without reading any values.

Hi, I have an innovate AFR gauge , it ran fine for a couple years and now when I go over bumps on the road it will read 7.8 + - , sometimes it will beep and flash, then resume normal readings. I tried replacing the sensor but the same issue happened with the new sensor. Any ideas? Bad wiring?

Mines reads 8 then resets. After it reset it reads 8 again and repeat?

I got a small problem rn. I bought My 2002 subaru wrx and it came with this and when I am running the vehicle It runs fine but the sensor is just showing P00 or P01 and sometimes works but fluctuates alot like 11.1 back and forth to 15 or 17 then just does ( - - - )

hey man im having trouble with mine the gauge is stck on 14.6/7 even cruising it doesnt move at all .what could be it? gauge or the sensor i just dont want to buy parts for extra .. any help would be much appreciated thanks !! @HotDamnRacingTeam

When I start mine it is at like 15 then slowly drops down to 10.0 after a few seconds then just gets stuck there. I drive and it just stays at 10.0 until I turn off the car then turn it back on and then after a few seconds it does the same thing again

I replaced the sensor and went through the wires. The only thing that I haven't replaced is the gauge and even my laptop is reflecting the gauge. It's stuck on 10 even with the sniff test

All right..

yeah these sensors are garbage juice , when its stuck on 14.7 when the car is on it stays there, gotta get a replacement :(

So mine will do 14.7 turn on and then lean out after running and stay - - -

With mine it is reading fine for a few seconds and then leans out and won't read anything anymore. That a sign of a bad O2 sensor

I wanna know where to check for the ground

Fellas and Fellets 😂

Mines is stuck at 10.0

On my 2end aem o2 sensor they all brake

What is the problem when the guage goes from 14:7 then after a minute running it drops to 10:0

Damn my gauge is bad then, mine does 14.7 on cold start then 5 sec later it just goes all the way to lean

dammit...so i guess my gauge is bad. i swear aem has severely dissapointed me, two 340lph pumps were doa, aleready gone through two sensors and now the gauge is toast. they should just stick to making intakes at this point, not one aem product ive purchased has worked.

FYI. AEM will not replace o2 sensor under warranty. I paid $155.00 for my gauge kit and had to pay another $121.00 to replace my faulty sensor. Not a happy customer.

I tried the same method as you but my gauge stays at 14.7

My gage reads fine for like 5 seconds then leans out

Oh fuck. I’m just running super lean😂

Whats the sniff test? Lol

You did nothing to help

What if the gauge just reads “sense”? I can’t find a solid answer anywhere