I'm going to be installing an Autometer A/F gauge and according to the directions it say's to tap into the wiring harness wire for the oxygen sensor, have any of you guy's done this before, and which color wire is it? Also, where is a good place to drill into the firewall to get to the fuse panel, or is there a better route to go without drilling into the firewall. I will entertain any shortcuts if any. Thanks for your time and answers to these questions posed.

 

I think we tapped into the O2 sensor directly for mine.....easier then cutting the harness splicing into the harness.

 

How many wire is the sensor itself? And which wire is it. I'm going to be using the drivers side oxygen sensor that's in the header collector, did you wire tie to the sensor.

 

A general recommendation... do NOT tap into the sensor wires. They are hard to solder, and the point where they enter the sensor also allows the air required for the sensor membrane to enter. Splice into the wiring harness, anywhere from the PCM connectors to the O2 sensor connectors.

The driver's side O2 signal wire is purple/white and starts at pin C20 on the PCM (gray connector).

The passenger side O2 signal wire is purple and starts at pin C8 on the PCM (gray connector).

Shoebox has pinout diagrams on his "Tech Pages".

http://shbox.com/1/4th_gen_tech2.html#1995_pcm_pinouts

To be able to read both sensors, one at a time, get a single-pole/double-throw switch and connect the gauge signal wire to the center and the O2 sensor leads to the outsides.

 

I wired mine to the drivers side oxygen sensor and basically ran the wire up to the windshield. If you look under the hood where the plastic piece meets the bottom of the windshield there is a part in that plastic piece over on the right side where it has sort of a hole in it and is blocked off with a piece of foam. I put the wire through there and then it came out by the rear view mirror and from there I stuck it under where the weather stripping begins. Then it is by the fuse box and can be wired under the dash. The only visible part of the wire is where it comes up to that plastic part of the windshield but it's not very visible on my car because I used black wire and my car is black. The wire is ran further then if you were to drill in the firewall but I think my way is easier.

 

Everything went fine except the connection for the fuel pressure gauge. The sensor threads are a fine thread 1/8 NPT type and the schrader valve thread is 1/4 coarse thread so I'm thinking I need a coupling w/ 1/8 NPT type fine thread on one end and that 1/4 type thread on the other end in the form of a 90* angle. Where can I get that type fitting? Do any of you folks have a part # or maybe you nitrous guy's know of what type of fitting I'm looking for? I looked in all the help sections of several different auto stores and came to a stand still. Can somebody please help me out, desperate and frustrated.

 

casperselectronics has the A/F pigtail.
Look its 16 bucks.
I would never cut anyting in my wiring harness.
https://www.casperselectronics.com/M...camaro1996upv8


Chris G.

 

I don't need the pigtail, I need the female to female fitting from the 1/4" schrader thread to the 1/8" pnt thread on the A/F sensor, it's basically a custom made fitting.

 

The only place your probably going to find that is at a hydraulic shop.
That's where I go when I need something odd.


Chris G.

 

NO. The Schrader valve connection is NOT "1/4 coarse". It is a -4AN fitting, and you MUST use an "-AN" style fitting to connect to it. I know I've posted this info here many times before.

My recommendation is the NOS part #17535 -4AN 90-degree swivel fitting. Remove the core from the Schrader valve, then screw on the fitting. The fact that it is a "swivel" type allows you to aim the connection in any direction you want. With -AN fittings, once they stop threading on, you ar done. Trying to over-tighten them will do nothing, except most likely break the Schrader connection off the hard line.

With the 17535 fitting, now you have a -4AN fitting pointing off to the side. You can get a -4AN to 1/8 NPT adapter, and screw the pressure sensor (or gauge?) directly into it. Part I don't like about that is adding the load to the Schrader. Get a short braided S/S hose with a -4AN connector on one end, and a 1/8" NPT on the other. Get a common brass 1/8" NPT coupling in any hardware store, and connect the gauge (or sensor?) to the hose. Now you can mount the gauge or sensor where its out of the heat and protected, and won't snap the Schrader connection of it something hits it.

 

Injuneer you are the man, a couple of ?'s, have you ever seen the hose I need around or do I have to have it specially made? How do you remove the schrader core? It would be perfect if I can get a 2" steel braided line with the-4AN female on one end, and the 1/8NPT on the other end.

 

The Schrader valve is just like a tire valve, and you use a tire valve core tool to remove it.

The hoses are available on eBay for very reasonalbe prices. NOS and others only sell standard lengths like 18". Not sure why you want a 2" long hose..... what are you trying to connect to it - a gauge or a sensor?

 

Didn't you say in your above post that to get a short piece of braided hose?

 

Yes.... short enought to allow you to locate the gauge where you can see it and read it (or to locate the sensor away from the heat if that's what you are talking about). 2" doesn't get you too far from the Schrader valve. I used to have the sensor for my AutoMeter electric fuel pressure gauge mounted over near the PCM, with the wires into the car through the grommet behind the PCM. Took an 18-24" line.

Now its on a bung welded to the passenger side fuel rail, but that's sort of a high cost install.