I had a chance to check out my O2 sensor the other day, and it's pretty strange. I swapped it out with a brand new one, then realized that the stock wiring wasn't there. (Haynes manual says it's supposed to connect to a green/yellow wire, can anyone verify that?) The wire that it was connected to was completely bare inside a little length of tubing, and then met with some grey insulation and led back into the depths of the engine compartment. There was also some black insulated wire in the tubing with it, but that wasn't connected to anything! I dicked around a little bit and discovered that the bare wire (the one hooked up to the sensor) was sending .08 volts back to ground, even when the O2 sensor wasn't hooked up. I pulled off a vacuum tube and that number didn't change. The black-insulated wire, however, read .07 volts and dropped to .03 volts with the vacuum tube off, which is more normal. The only problem is that this doesn't tell me anything since they WEREN'T CONNECTED TO THE SENSOR!

Wth is going on? I hooked my new sensor up to the original wire it had been on (the bare one), but I don't think that the signal it's sending out is even making it to the ECU. Is my car just running without an O2 sensor? And is that why it's running incredibly rich and failing smog checks miserably? (5.0 CO 1600 HC)

 

Haynes has been wrong on wiring for the '7 before. The stock wire is usually black with a yellowish connector intended to lock into the connector on the O2 sensor. If you search for pics of the sensor location or look through the diagrams in the FSM you might find where it's supposed to be.

 

Both a haynes and a chilton's said that the wire is green and yellow. The OEM O2 sensor has been long gone and replaced with a universal one, so w/e connector might have been there is gone. I'll look in my factory manual for ideas, any suggestions in the meantime would be nice though.

 

I think I got a 'universal' O2 sensor for my '7 and it had the right connector on it. Like I said, you could look or ask for pics of what it should look like and where, and in the meantime you could post pics of your engine bay in case you're missing something, extra sets of eyes can be helpful with things like this.

 

The O2 sensor won't even throw a check engine light. I know several people around here that don't have it hooked up at all. It's no big worries. Then again, we don't have to pass emissions and throw flames on a daily basis.

 

uh removing the o2 sensor is retarded unless you have a standalone. it just gives you bad gas mileage. the o2 sensor isn't used under load anyway

 

The color is a GRAY, shielded cable with a Black center conductor. Not green/yellow.

 

He's doesn't WANT to remove the O2 sensor...