Hello guys, i have been researching the internet for few days now and i cant find the right way to connect my afg to my 99 civic with obd2 b16a2 motor

i usally find threads and DIY with afg with 3 wires

1 red - Power
1 black - Ground
1 purple - 02Sensor

but mine is wierd it has 4 wires

1 red - Power
1 black - Ground
1 purple - i guess its the 02signal
1 gray - no idea.

so i have plugged it in and i did put a wire from the purple one to the o2 in the ECU solid white wire there and the power and ground is wired all reddy

but when i turn on the car its like its not plugged just stays rich like it has no signal. the gray one is not wired up i have some pictures of this here

pics = http://einar.vefmynd.net/maelir/

any ideas ?

 

what brand is the gauge? most likely the grey is for dash lighting, meaning the backlight would come on when you turn on your headlights at night. have you let the car warm up to temp? the o2 sensor takes some time to heat up before it can start reading properly.

PS - im sure a ton of people are going to come on and flame you b/c narrowband a/f gauges are useless and aren't able to give accurate readings

 

You know that those are next to useless for actually measuring air/fuel ratios? (had to say it.)
https://www.google.com/search?q=how+to+wire+air%2Ffuel+gauge&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-USfficial&client=firefox-a
http://faculty.ccp.edu/faculty/dreed.../afr/index.htm

Might also be similar to this.
http://www.autometer.com/

Did this gauge NOT come with instructions?

 

im not sure of the brand i bought it second hand and you can just see the pictures of it i dont think its the lights becuse the show up when i turn on the car.

i have made it warm up, and i know all about that hehe. im just saving up for a AEM wideband just so gay to have 1 empty gauge in my post so i just got this one very cheap untill i get a better one

 

if i connect the gray one to the signal i just get this

 

honestly, its going to be near impossible to help without knowing the brand or having instructions. i looked at the autometer, which have four wires as well. red, black, purple, white. so i assumed your gray mgith correspond to their white since everything else matches.

where are you getting signal for the purple wire? ecu? o2 sensor harness?

 

From the ecu. solid white wire in the blue connection.

im having a cel now and i cant find the little blue pin to read the cel might have fallen under somthing down there but i might think the meter is correct connected now but the o2 sensor is bad

 

What? I have never seen an O2 sensor go bad from hooking one of these up.

 

Do you think the o2 sensor is bad because the reading your getting from the gauge? I wouldn't trust anything that gauge shows

 

No i think i might have done something to it when i was putting the gearbox back in i was rebuilding the gearbox and new clutch and everything

 

you need to pull the code and report back. sounds like you have created a CEL due to something in the o2 sensor wiring circuit. the sensor itself cannot go bad from adding a gauge but the ecu is probably not getting the correct signal since you tapped into the harness. gauge could be wired incorrectly, throwning an o2 code.

you were probably better off with an empty gauge pod

 

First make sure you get all the wires correct before proceeding - wires tapped into the O2 sensor leads MUST BE SOLDERED. If not, oxidation will cause ohm/voltage issues later on.