I had a code of P0154, so i replace the passenger side O2 sensor... in the process i found that a wire had been cut on some sensor plug (never cut by me) anyways its the green one in the pic as you can see... the plug has 4 wires, a black, purple, blue and the green one that had been cut... I'm assuming this is a ground wire? what does it run to? what should i go about treating it? thanks...

 

Looks pretty suspicious to me. I would look down in that harness for the rest of it. Whoever did that may have even cut what was sticking out of the harness. Come to think of it though, if I was vandalizing the car in that manner, I would have cut the wire right next to the connector. Is that the o2 connector?

 

I've looked through the electrical circuits and can't locate a 4 pin connector that has that particular color combination on it's wiring. It's not any of the O2 sensors apparently as they all have a tan or tan/white color on at least one of their wires. I've looked at TAC module, crank sensor, transmission reverse lockout solenoid, HVAC, TPS, Knock Sensor, fuel/ignition and starter circuits just to name a few. No luck.
I can say pretty confidently that green is never used for ground connections. Only black or maybe black with a white stripe is ever used for a ground connection. Power leads are usually either orange, red, purple or brown for higher current circuits, and sometimes pink or blue for lower current circuits depending on the system. Most all the other colors are for the control or data signals, etc. Sometimes there may be variations on this, but this is a general rule on color usage.
Without more info as to where the wire harness goes, it's going to be hard for me to tell you much more.

Anybody else have a clue here?

BTW, it's possible that the green wire is unused in that particular circuit and has no intended usage and/or voltage on it.

 

I cant answer that , But pm Bill Currey or someone else may wanna Chime in

 

I put my money on 02 sensor connector. That is the only plug to my knowledge that is in that general area and is flat like that.

 

That's what I thought too but the colors don't jive.

 

but LoneStar, could it be that maybe the wire that's cut isn't green, but its been discolored from the heat of the header? Or maybe it was an aftermarket 02 so the color code is off? The 02 connectors are the only thing I can think of up in that area.

 

I can't see your pic at work.........but..........I have found this on my 97before.

 

Anything's possible I guess, but the pic sure looks green to me plus RrCoX22's statement about it being green too. Also, it appears from that pic that the connector body is on the chassis (factory) side of the harness not the O2 side.
Hmmm, dunno for sure what that little puppy is. Unless maybe the color coding on the wires was changed from one year to the next - I was looking in my '99 shop manual - but that doesn't seem likely.

Mystery for now.

 

Yacko! Ungood!

The OP's colors as he states them, do seem to show up in his pic as the same.

 

ya i can't make it out what its connected too completely forgot while i was under there... it is for sure green the wire that has been cut

 

so i guess its a data/voltage line... and looks like i needs to get a new pigtail plug... but does anyone know is this for the O2?

 

also does anyone happen to know the part number for this pigtail?

 

Until you can find out more about it, I would just leave it alone for now. Unless, that is, you're having some sort of malfunction in a system somewhere. Then of course that would be a clue as to what it's tied in to.

BTW, you could also unplug the connector temporarily to see what DTC or malfunction you get too.

 

its gotta be for the O2 sensor cuz im still throwing that code and it relates to voltage readings although i have no clue on what part number that pigtail and wiring is

 

Not sure if this helps you I'm a newbie and I only have a C4, but I'm right in the middle of a similar problem. If this doesn't help you, perhaps it will help someone:

My 'pigtail' was fine, however I needed another 'connector' as it's sold, (goes from pigtail plug to car's harness) about $35, you get the female end of the plug to the pigtail and about a foot of connected wires. Mine happened to be all white, connectors included. The part number for my '96 was 1210-2741 and it was just under $40.

02's come with pigtails or you might can get separate. Dont' know the pigtail part number tho