6605stang

SO I'm muddling through my first gauge installation on my 07 SGT (w/Whipple). Installing Boost/Vac, AFR, and Fuel Pressure Autometer Nexus gauges. My question is what is the best route for the wire harness of the AFR gauge? Currently I have the 6400 module mounted under the driver side dash and harsness going out the large bung/grommet that goes into the driver side wheel well. But then it seems there is no good way to get down to the rear 02 Sensor bung, which is what I believe I'll be using for the sensor. Unfortunately there is not much slack in the harness and anyway I slice it it needs to go near the steering column or the exhaust manifolds. Neither way seems like a good way to go.

Can anyone that's done this recommend where I should go with this harness?

Thanks, JR

moosestang

I have not done it, but the shifter is right there, why not route it up through the center console and too the dash?

6605stang

You know I didn't think of that. I'll take a look and see if there is a way to route it there and keep it off the drive shaft. Thank you.

Additionally, where to install the sensor for the gauge. Can I replace one of the rear O2 sensors? I'm not sure if they are disabled on my tune, but I ran several key cycles with one disconnected and it hasn't thrown a code. And is the rear O2 sensor location a good spot for the AFR sensor, or do I need to have a new bung drilled/tapped further upstream (ahead of the cats)?

moosestang

I'm not sure if the down stream o2 location is going to give you a good reading. It will surely read leaner there than in the upstream 02 location. Your wide band should have a narrow band lead that can be plugged into your stock 02 connection. It's supposed to emulate a narrow band signal for the ecm to read. I'm not sure how well that works in the up stream location though.

Hopefully someone that has done this will chime in. I was going to install one in the downstream 02 bung, but never got around to it.

tbar

You want the sensor as close to the engine as possible. If you still have cats put it before the cats

moosestang

Ideally yes, but my car dynoed 10.8:1 AFR using a sniffer in the tail pipe, so how much more rich could it be before the cat?

If I were using it to tune the car, then I'm sure before the cat is best. If you just want to keep an eye on the AFR, then the down stream 02 bung is really, really convenient. Especially if you have to remove the sensor every now and then to recalibrate. Removing either up stream 02 sensor is a real bitch!

6605stang

That seems like sound logic to me. If every time I've had it tuned it was either plugged into the rear O2's or the tail pipes, I can't imagine why it would be fine for the gauge connection.

NEXT question, since you guys are so good at this. I've got a red constand and yellow ignition wire I need to tap. Can either of you recommend a good spot to splice into under the driver side?

moosestang

Sorry, I suck at wiring. I just learned how to properly solder two wires together. I've been using crimp connectors my whole life.