O2 sensor harness help

[87GrandMarq]

I have a hard time getting parts locally and the po threw away the o2 harness so I got one from a 93 mustang gt with an aod. The issue is that Im not sure if its pinned the same and I know if you put 12v on the wrong pin the ecu could fry. Does anyone have a pinout of the body side of the harness or if someone could measure voltage at the o2 sensor side of the harness?

Also how do you guys remove o2 sensors on stock manifolds? I cant seem to get anything in there. Thanks.

[GM_Guy]

Snap off the stem from the old o2 sensor, pour some seafoam PENETRANT into the well, wait, try and crack it loose, let penetrant sit a bit more, back and forth to remove. The seafoam penetrant softens carbon deposits extremely well that let you slowly work the sensor out.

1989 mgm o2 wiring colors; Grey/Yellow 12v Black/LightGreen Ground Dark Green/Pink Signal
Looking at rockauto, the same o2 sensor is used in the boxes as the mustangs.

Alex.

[87GrandMarq]

I dont have a dark green and pink wire and I have 2 more pins that dont connect to anything on the o2 harness side of the connector. And there are two pins that dont go to anything on the other end. There was a jumper there but I removed it because the 87 mustangs didnt have one. It looks like the top 3 pins are the only ones that really matter.

Also just getting to the o2 sensors with a wrench is nearly impossible. Ill see if I can get one in there.




Sent from my iPhone using Tapatalk

[87GrandMarq]

I connected it the way it is with the loop removed and so far so good. I guess the pins are the same between the mustang and grand marquis. We’ll see how it goes.