Is my Air/Fuel gauge working correctly?

Finally got the Auto Meter Air/Fuel gauge rigged up (it was given to me.)

Something doesn't seem right though. I understand that narrowband air/fuel guages aren't accurate but this doesn't seem to be doing a whole lot. Looks like the people that ran the wires reversed the purple/red. The blue wire running to the o2 sensor was spliced into the red on the gauge, and the red wire was spliced into the purple on the gauge. So I reversed those and she lit up.
This is what it looks like at idle and during normal driving, with the bottom 2 LEDs flashing staggered as you can see in the video.
View attachment 233077

At wide open throttle the lights move up to about the middle of stoich. I read that at wide open throttle it should stick around the last 2 lights of rich...The picture above is what it looks like 80% of the time just driving casually.

Here is a video of the gauge at idle, and what it typically looks like.
0116000047a.flv video by thealmightyhubbard - Photobucket

Sorry for the cell phone quality media.

The purple wire was ran through the firewall and down to the O2 sensor itself, not the PCM. I can't get under there to look but I assume the wire should be ran to a downstream O2 sensor since exhaust from all cylinders flows past there? Car has no cats if that makes any difference.

Or is it running a little lean? I had 2 O2 sensors replaced when I put the O/R X on because the downstreams were seized to my old pipe. I'm not sure if the 2 new ones ended up upstream or downstream on the new Magnaflow O/R X.

When the engine is at heavy load the monitor should indicate rich. At
cruising load the monitor will appear to be bouncing back and forth
between rich and lean.

Click to expand...

In its simplest form, the gauge is a color coded voltmeter, which lights up the LED(s) that correspond to the voltage that the gauge is sent via its signal wire. On most late model vehicles, the sensors are quite sensitive, and capable of responding very fast to a change in A/F ratio. This makes it appear that the LED's flicker in the different ranges, and this is normal. The gauge is showing the voltage it is receiving from the sensor, so more often than not it will appear that more than one of the LED's are lit, or that the readings are being shown to be in more than one section. Provided the gauge is connected properly (good power and ground) and that the connection to the O2 sensor signal wire is SOLDERED, this operation is normal. Usually, the only time the gauge will not show so many LED's is when the engine is at WOT. Instead, the gauge will pin the last few green LED's of the rich section. With time, as the O2 sensor degrades in sensitivity, the readings may be more spread out on the gauges display. Also, this gauge is not in any way designed to be used as a tuning tool, but more of an aid for the overall tuning of the engine. This gauge, when used in conjunction with either an EGT gauge or even 'reading' the condition of the plugs will help you determine the optimal A/F mix for your vehicle. Keep in mind the above only pertains to computer controlled, later model vehicles.

Click to expand...

http://i295.photobucket.com/albums/mm142/thealmightyhubbard/IMG_1544.jpg

This is about where it sits at idle and normal driving. This is really no fluctuation, just mainly the 2 bottom lights blinking and the others up to Stoich partially illuminated.

Here's a video of me leaving Wally World and then doing WOT 2nd-4th. As you can see it kind of jumps to Stoich after a bit and then falls back down to the typical lean. I have never seen the Rich lights illuminate.
YouTube - MVI 1550

And this is where it fell back to after the WOT run and never jumped again.
http://i295.photobucket.com/albums/mm142/thealmightyhubbard/IMG_1551.jpg

I called the shop that did it and I'm going to bring the car back tomorrow. He tapped directly into the O2 sensor, not the PCM. Said it gave a more accurate reading or something of the such.

If it comes to it I'll just tap into the PCM myself, if I can find it haha I need to get another Haynes manual.

What holds Wire 87 into the PCM? If I go that route I would like to pull it out and use one of these.

Or do I just leave the wire in place and cut a few inches back and splice from there?

Do pins 60 and 87 on the PCM correspond to L/R upstream or downstream sensors?

4tun8 said:

Sweet pretty lights. Pull that thing out and get a wideband.

Click to expand...

It was free. I think I have ADHD so I like the pretty lights

When my car becomes worthwhile I'll upgrade to a WB.

4tun8 said:

I'm like that too, I like pretty lights, but I seriously wouldn't go through the hastle of installing it. It is THE most worthless gauge you can buy. It literally tells you NOTHING.


You can get a good wideband from 200-250 dollars. My AEM wideband cost 250 and has data log functions. I had it setup to log in my data log (evo scan).

I wish they made something like Evo Scan for mustangs, I could install a new turbo and have the car street tuned using data log labs, and evo scan in like 2 hours.

Click to expand...

Well 66% of it is already done and my A-pillar is already drilled so there's no turning back. All I have to do is run over to the PCM and splice a simple wire with one of those little plastic splice-clips. It's something to do

SaleenGT2001 said:

it is just a light show. it should bounce from rich to lean constantly

Click to expand...

But it makes the car look fast

Yeah I used your write-up to tap into the 87 wire The power and such was already done. However, I used one of those little clips instead of splitting the wire and splicing in manually.

However, something still doesn't seem quite right. It is doing 10 times more than it was before I cut the wire from the O2 sensor but...

The car has been running for about 5 minutes. It will bounce back and forth between lean and stoich and at WOT in 2nd gear it pegged dead center of stoich, 1 LED.

Is this normal? I've yet to see the Rich LEDs light up but I've only taken it around the block and did a quick 2nd gear pull from around 30mph.

EDIT: DISREGARD...Ended up being a faulty gauge it seems I was using the Ultralite that was given to me (which I believe to be a knockoff due to the plastic bezel) because I was told my Phantom didn't work (the people that did the electrical work had the purple/red reversed where it connects to the gauge). So I went ahead and extended some wires and hooked the Phantom back up with the wires where they were supposed to be. Works like a charm. Bounces between Lean and Rich like it's on crack, pegs Rich when I got WOT and illuminates 2-4 Lean LEDs on deceleration.

What a pain in the ass that was for a stupid gauge I didn't even spend money on and that is pretty much useless. Oh well, time to go enjoy the light show At least I'll have an idea when 1 of 4 of my O2 sensors goes bad haha and that damn thing better keep pegging Rich at WOT