o2 sensor removal
 

Okay i feel like a complete tool here but does anyone have any tips.

I have 2 different o2 sensor sockets but they don't work. I'm not the largest guy either...

Not quite sure where to go with this. What isn't working? If they actually fit on the sensor, but you can't get it to budge the try a cheater bar, PB Blaster, and finally heat.

No room for a cheater bar, unless using only an open end wrench, it's 3/4 right? But my 3/4 wont fit, seems a little too small. I put an adjustable wrench in there, and a cheater, but it slips.

it's metric :nuts: 21mm I *THINK*

A wrench works best to bust loose an old sensor. Put open end of wrench on o2 sensor, and use a sudden sharp motion to bust it loose. A good sharp hit to the end of the wrench or sudden jerk will do it.

Optionally you can run the car to get the exhaust hot. The sensor should be easier to free when the exhaust is hot. However, then you have to deal with not burning yourself. Should not be necessary, use as last resort.

Make sure replacement sensor has anti-seize coating on the threads. Better sensors come with some on the threads.

My O2 wrench is a 7/8".

7/8 = 22mm

So I guess it's a 22mm wrench. Hey, I pulled it from memory

is there any harm in just cutting the wires off the sensor? I'm replacing with an WB o2. Also, no avail, i got it to hurt a little than it halted, i'll try again tomorrow

You should be able to just cut the old wires sure but leave abit of room to make sure you can splice back later if need be. A hammer might help.

Tom,
Did you get it off? Can you drive the car? I might need to borrow your O2 sensor. If you can get the car to my house, I'll get it off for you and plug the bung so you can drive it back.

Does someone have a pic of the main O2 connector under the hood? The guy who installed the Motec in my car removed the sensor like Tom is doing and ran with just a WB. I can't find the connector under the hood amongst all his other wiring/sensors. I need to reinstall the O2 to get emission tested. The O2 sensor that came with the car has the connector cut off so I don't know what I'm looking for under the hood.

Thanks,
Frank

frank, you can if you can get it off, i can drive down right now

mine is a blue wire comming of the injector harness. 13 bucks at autozone for a new OE replacement sensor.

Is the connector on the injector harness side (pax)? I don't need a replacement, I just need to find the plug so I can re-wire the OEM sensor in and get rid of my CEL for the emissions test.

Frank

Things may be different on your NB (that you stole and I still hate you for it) but my o2 harness will fall back behind the head if disconnected. So you might have to fish for it down between the head and firewall. I believe it runs into the ignition harness. Here's pics of my single wire harness, yours would be a 4 wire. For reference, the hose in the near field is the fuel return from the fuel rail.
https://www.miataturbo.net/general-miata-chat-9/stock-o2-sensor-6115/

Thanks. Guess I coulda searched. I remember retroing my '90 to a 4 wire from the single wire. I'll go fishing tonite.

Frank