i am wiring my air fuel meter and if i have the o2 sensor wire ran to the harness and the a/f guage wire spliced into that the meter reeds full lean, if i disconnect the connector to the harness and run the o2 sensor to the meter wire, it says full rich. when the meter says either full lean or rich the lights do not move at all, can someone help me out here, i feel like a total dipshit

 

you're probably running rich..

the ones i've seen have like a red, black and some other color wire (purple?)
red gets battery power, black is ground, the other wire goes to the o2 sensor.

 

Check the ground from the meter to the ECU.
The narrow range AFM only uses 1 volt to go from full lean to full rich.
An indirect or weak ground or signal wire will cause errors.

I was a bit **** & ran a shielded (coax) from the ECU to the meter.

 

all the connectors are tapped and sealed from air

 

^this is how i have it wired

 

bump

 

Maybe I misunderstood the picture, or maybe this doesn't even matter, but why did you splice into the O2 wire after it goes into the harness? I wouldn't think it would make a difference at all, but when I hooked mine up I just spliced into the wire coming up from the O2 before it went back into the harness.


So it goes:

O2 ------wire-----spliced in for meter------wire-------harness


Still don't think that should make a difference, though. But I had no problem doing it this way, worked right away no problems and has been working since.

 

alrite well im gunna give it a shot that way and ill get back to you guys in like 10 minutes

 

no luck with this^

 

Got a DVM?
Check the signal to ground voltage at the meter, with a warmed up & running engine.

 

isnt it grounded though because the meter lights up?

 

bump

 

A/F meters should be connected at the ECU, not the sensor. By not messing with the shielded cable in the engine bay, you avoid potential problems like this.

 

Do you have a narrow or wideband? If its a narrow band, I would just throw it away, it's pretty much just a pretty light display..

 

It works at WOT during lots of load just fine. When not at WOT, though, its a rainbow gauge!

But it can work to find out if you're running too rich/lean going like uphill, or on the freeway doing redlines through 1st, 2nd, 3rd, and shifting into 4th and letting off about 120ish, I did that a couple times.

 

Other than the potential problems there isn't a difference between being at the sensor or the ECU, right?

 

Thats cool, have you compared it to a wideband unit in your car or on a dyno? I've just always been apprehensive of narrowband A/F gauges..

 

I'm getting a wideband O2/data logger in the next few weeks or so. The narrowband meter doesn't work for **** when just driving around normally or cruising, I'll give you that. But with lots of load and at WOT or going up a hill or something, it's accurate.

 

Um... your o2 sensor might be old. My gauge acted the EXACT same way. It reads absurdly high even at WOT. I'm putting in my new o2 sensor next weekend. I only get voltages up to .85, and when I'm at idle, I get either .00 or.01

 

If you honestly think it's just a light show, then you simply don't understand what you're seeing or how to use that info. If you understand the limitations of the sensor, and how to interpret the readings, it's very useful info.

This is exactly what I meant above. You don't actually understand what you're seeing, so you think the readings aren't useful.
Correct. If it's good enough for the ECU...
Completely wrong.
Even more wrong!

 

Hmmm, everything I've read has been lies then.