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Air/Fuel Guage

sir_break_a_lot

New CEG'er
Joined
Oct 25, 2001
Messages
14
Location
New York
Ok, so I bought this air/fuel ratio guage for the ole zetec and I'm looking at the instructions and a few questions are popping into my head. Where is the signal wire to the O2 sensor in the harness? obviously the guage wire isn't long enough to run allllll the way to the sensor itself, nor is it intended to.. so does anyone know where to hook it up to in the harness wiring?? also what would be a good 12V wire to tap that is run through the ignition so it only works when the car is on?? muchos gracias!!
 
Ignition.....test the wires going under the dash.

o2- the sensor wire is white (coming from the front o2 sensor) and make sure to tap it after the harness.
 
thanks

thanks

has anyone actually done this?? i read the haynes book and yes it's white but there are also other white wires too. does anyone know exactly which one it is before i accidently destroy my entire harness??? and when you say after the harrness... what's that mean.. like right about the ecu?? i have no idea what you mean. sorry. thanks though! :)
 
I actually did this. You see the o2 sensor in the front? The wires have heatwrap around the wires which go to a harness attached to the fan assembly. There are two white wires, black , and a gray wire. Splice into one of the white wires AFTER the harness (on the other side WITHOUT the heatwrap).
 
thanks

thanks

but even though I like to consider myself pretty technologically and mechanically inclined.. I don't want to risk laying up my car while it's my only form of transportation. any pictures?? would be big help :-D
 
Don't worry about the sensor wire down by the sensor. Theres no need to run wire all the way from there.

Tap into the wire where it goes into the ECU. It's PIN 87 white/red wire. Splice into the wire about 5" away from the ECU and you should be good to go. Remove the plastic vent covering your cabin filter and wiper motors. Theres a rubber groumet underneath the wiper on the driverside. Cut a hole in the groumet and run the wire through it. It will come out just above the brake pedal, but you will have to crawl under the dash to see it. Also as far as your 12V source goes theres a spare output on the fuse panel that is directly tied to the ignition switch. Tada, enjoy your A/R gauge. :cool:
 
ignition wire

ignition wire

where is this mysterious extra ignition wire I can use to tie in the guage?? I have all the other wires hooked up so I'd hate to mess it up now! :)
 
DSC01699.jpg


just got these from the states, good price:laugh: so thanks for this post.....top 1`s the air/fuel gauge.
 
I just tapped into the actual O2 sensor's harness on the white wire there. It works for me like that. If you need, I can take a picture.
 
Unless you have a wideband air/fuel sensor, this is useless. All it will do is cycle back and forth with the 02 sensor output. It will not tell you if you're running rich or lean during normal driving because it will continuously move throughout the range.

Besides, are you running any kind of forced induction at all? If not, what's the point, the computer monitors the air/fuel ratio and keeps it just slightly rich of stoichiometrically even. It knows what's best, so why worry?
 
Unless you have a wideband air/fuel sensor, this is useless. All it will do is cycle back and forth with the 02 sensor output. It will not tell you if you're running rich or lean during normal driving because it will continuously move throughout the range.

Besides, are you running any kind of forced induction at all? If not, what's the point, the computer monitors the air/fuel ratio and keeps it just slightly rich of stoichiometrically even. It knows what's best, so why worry?

Well, First, this gauge has told me that the car was running rich or lean, yes it does cycle through, but thats because that is what happens when you run it on a non broad band O2, but it will also stay directly on lean or rich when you runi it too lean or rich. My car is not FI, but I got the gauge to help me monitor the ratio after I got the adjustable FPR.
 
The check engine light will let you know if the car is running rich or lean. Assuming all the sensors are working correctly and the engine is warm, it will run at stoich. If something isn't working properly- a vacuum leak causing a lean condition, for example- you'll get a code.

People with turbos monitor their air/fuel ratio so they don't pop an engine running too lean because the injectors can't keep up with the volume of air being forced in. You have a stock engine and a stock fuel system- I promise, you don't need to worry about running too lean. It will keep up just fine.

If you like the gauge, great, but people thinking about installing one shouldn't expect it to be some kind of accurate monitoring system.
 
The check engine light will let you know if the car is running rich or lean. Assuming all the sensors are working correctly and the engine is warm, it will run at stoich. If something isn't working properly- a vacuum leak causing a lean condition, for example- you'll get a code.

People with turbos monitor their air/fuel ratio so they don't pop an engine running too lean because the injectors can't keep up with the volume of air being forced in. You have a stock engine and a stock fuel system- I promise, you don't need to worry about running too lean. It will keep up just fine.

If you like the gauge, great, but people thinking about installing one shouldn't expect it to be some kind of accurate monitoring system.

Yep non wideband 02 gauge about as useful as a LED light show (that' essentially what it is). If you really want to put a gauge that has some use get an Oil Pressure gauge, since the idiot lights come on when pressure has dropped so much damage has been done.
 
Yep non wideband 02 gauge about as useful as a LED light show (that' essentially what it is). If you really want to put a gauge that has some use get an Oil Pressure gauge, since the idiot lights come on when pressure has dropped so much damage has been done.

Yep. Water temp guage isn't a bad idea, either, since the ones Ford provided are notoriously inaccurate.

If, however, you're running an ATX, then a fluid temp sender and gauge is almost a necessity. You "splice" it in to the cooler return line.
 
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