Airfuel install did tons of searching everywhere

[kit99bar]

and could not find a install for this!
I know I need to tap the blue wire from my autometer air fuel to the O2 sensor somewhere
and I also know this mod is just a light show but I really don't want to do the EGT (not modd'n to hell)

so does anyone have help for the airfuel?

thanks!

[AREITU]

PM WRXG0blin, he's installed an AF meter before.

Your AF meter will read either super-ultra rich, or lean. Maybe when the ECU runs close-loop, you'll get a great light show. Automter makes AF meters that read 1 volt sensors, the WRX has a 5 volt wideband.

[djrez4]

I just did one of these last week.

You should have at least 3 wires on the back of the A/F meter. Red for power hooks up to the "ACC" wire on the clock plug (check the back of the clock for wire labels). Black is for ground. The other wire will have to run through the firewall and down along the transmission to the rear O2 sensor. It's located just in front of the rear catalyst. You want to peel back the covering on the wires that run from the O2 sensor to the first harness (follow the wires and you'll see it). There will be a blue wire in there. Make sure you tap the blue wire on the sensor side of the harness and the wires switch colors on the other side. The two black wires are grounds, the white is the heater power and the blue is the O2 signal. Check the attached MSpaint drawing.

[stealthmode]

I tapped the white wire on the o2 harness because of the ecu pinouts listed on this site. The blue one was correct though. Thanks.
Also, instead of going to the clock for the constant 12v, I found a large green wire just off the back of the fuse box worked great. I was glad I didn't have to go all the way to the clock.

[Rice Boi]

What is the point of wiring the air/fuel if you are going to wire it to the rear O2 sensor?
I've always thought you wanted to monitor the air/fule before it hits the turbo not after for turbo cars. Its not going to offer you much reference in anyway if you are going to do that. I gues if its running rich at the rear you are running realy rich truly. Also, I think it is perfect that the WRX has a wideband front O2 sensor. All you need to do is buy a wideband air/fule and tap it to the sensor and your set. That will offer a very good and fairly accurate tunning reference as well.

As a side not, I would not want to use the rear O2 sensor as a tuning reference since if your car can run to rich which will cause the eccesse gas to literly wash off the oil off the cylinder walls and altimately cause engine damage and compression lost.

[stealthmode]

I personally feel like the narrow band air/fuel gauge is a waste of time. It won't really be accerate at all, so it really doesn't matter where it's located. I did this install on my mother in laws wrx that was basically for "the gauge look", not an actual tuning device.
For tuning I would only use the wide-band.
The excess fuel washing the oil out of the cylinders sounds pretty far fetched as far as hurting a motor. I think you would have running problems before your so lean that running rich would "wash" the oil out of the cylinders.

[chibich]

So do u tap the 02 sensor after the down pipe, or is there one on the headers that would be beter to tap?

[Rice Boi]

If you have a narrowband (1V) then yes, tap it directly to the O2 sensore on the downpipe. All you need to do is tap it to the wire were it runs to the ECU then you don't have to run any wires out of the capin of the car. But its only good for show. If you want one for tuning, then get a wideband.

[chibich]

I have a wideban A/F gauge

[04blackWRXchic]

Why don't you tap it to the line coming out of the ECU? Its B17 (rear o2 sensor signal). Just look for the ECU pinout on the forums. I believe there are 4 or 5 sepeart harness going into the ecu. Just look for the ecu pinout.

That way you donw have to run wires through the firewall and down the exhuast. Don't have to worry about waterproofing the connections or anything like that.

I just did a autometer air/fuel install the other day and I tapped the wire going into the ECU. Very easy.

[Rice Boi]

You can't just tap a wideband guage to the stock O2 (downpipe). The stock O2 is a narrowband. It's not going to be acurate at all. You need to buy an O2 wideband sensor as well (about $75-$85).

[Jeffros Spec V]

What he said ^^^^ but..mine was fairly accurate with what the general consensus was. At 75% + throttle the air/fuel gauge was more towards the rich side.