Missing front O2 Sensor AND Wiring -- What to do?

[arbalest]

Ok, so I figured out why I'm getting bad gas mileage. I bought a new O2 sensor today and went to install it, only to find out, I don't even have one!

I have a plug in place of where it should be, and NO trace of WIRING left anywhere.

What should I do?! I'd like to install one so I can get some decent MPG's.



Does anyone have a diagram or picture of where the wires stem from, and where to get the wires and plastic connecting plugs?



Thanks for your help!

 

[MrBoxx]

To the passenger side of the valve cover/head, behind the water outlet/thermostat housing, is where the O2 sensor connector usually hides. You may have to dig for it. If you've got a replacement O2 sensor, you'll know what the plug should look like, unless you got a universal O2 sensor, in which case, I recommend returning it and getting the OEM style one with the plug.

 

[arbalest]

To the passenger side of the valve cover/head, behind the water outlet/thermostat housing, is where the O2 sensor connector usually hides. You may have to dig for it. If you've got a replacement O2 sensor, you'll know what the plug should look like, unless you got a universal O2 sensor, in which case, I recommend returning it and getting the OEM style one with the plug.

I know where the O2 is supposed to be.. iTs just NOT there Someone plugged it off with a threaded plug.. The remaining attaching wires that should have a plug are missing as well. I searched all over... In, around, under the car. Its like they were stripped from the harness somewhere...

So my question is what to do about it?

 

[kenamond]

I know where the O2 is supposed to be.. iTs just NOT there Someone plugged it off with a threaded plug.. The remaining attaching wires that should have a plug are missing as well. I searched all over... In, around, under the car. Its like they were stripped from the harness somewhere...

So my question is what to do about it?

Nonono. The O2 *sensor* is on the driver's side on the O2 housing. This is what has a plug threaded into it. The plug (electrical connector) is on the other side of the motor where MrBoxx said. In stock configuration, the wires from the O2 *sensor* go up over the heat shield (if you have it still) above the exhaust manifold and down under the t-stat housing where it plugs into the wiring harness. The plug that it connects to is bolted to the passenger side of the head with a steel bracket and a 10mm bolt, but it's very hard to see and therefore very easy to not notice even if you're looking around for a plug.

 

[VETTE_50_TH]

PIC
Right underneath the thermostat housing should be the connection. From there to the o2 housing is where you want to thread the o2 sensor. I recommend the bosch o2 from advance auto.

James

 

[arbalest]

Guys, i'm asking what to do about it missing.

Its NOT there. No wires leading to anything, nothing... NO O2 sensor period!

There is a threaded plug in the O2 sensor hole. That is all that is there.

 

[ktmrider]

Guys, i'm asking what to do about it missing.

Its NOT there. No wires leading to anything, nothing... NO O2 sensor period!

There is a threaded plug in the O2 sensor hole. That is all that is there.

You keep missing their point.
Buy a STOCK ( not universal ) O2 sensor with the pigtail and connector. Once you see how long the pigtail is you should then find the harness connector for the O2 sensor under the t-stat housing. The harness connector is round with 4 wires and quite a ways away from the O2 housing.
Remove the plug from the housing, put some anti-seize lubricant on the sensor threads ( if not already done ), install the new sensor, route the pigtail away from the exhaust, then connect to the engine harness somewhere around/under the t-stat housing.
Check this link Virtual Tour of the DSM Engine Bay - Top index for pictures of the engine bay and items located within it. Specifically look at the "Exhaust Heat Shield" portion as it shows the O2 sensor harness running over the top and down/underneath the t-stat housing.

 

[diggerzmound]

I really doubt the wires are stripped out all the way to the firewall. Listen to where these guys are telling you that they are at and follow it back to the main wiring harness. If someone cut the factory pigtail off the wires will still be in the main bulk of wires.

Myself, I would hit up a junk yard and get the factory pigtail and use good waterproof splices and a O2 sensor made specifically for the car.

 

[arbalest]

I really doubt the wires are stripped out all the way to the firewall. Listen to where these guys are telling you that they are at and follow it back to the main wiring harness. If someone cut the factory pigtail off the wires will still be in the main bulk of wires.

Myself, I would hit up a junk yard and get the factory pigtail and use good waterproof splices and a O2 sensor made specifically for the car.

Thank you.


I just found the remaining wires.. The idiot clipped off the whole damn thing including plug. I've got like 4" of wire to work with!

Gotta goto the junkyard now