O2 sensor replacement (harness access)

[PStansberry78]

So... I assumed that replacing the O2 sensors in my 93' would be a reasonably simple project. The sensors are exposed and easy to get to on the bottom of the truck, and appear to simply screw in.

I haven't taken the old ones out yet, though, because when I went to disconnect the old one before removing it, I find that the harness plugs in way up behind the engine in the engine compartment.

What's the trick to getting to this? I can't seem to reach where the driver side O2 sensor plugs in, and I can't even see where the passenger side one does...

What say ye'?

 

[natenkiki2004]

My 1991 has a single O2 sensor, right before the catalytic converter. If that's the one you're talking about then the connection is secured on the transmission dipstick tube (I'm not sure if manuals have this too). In my case, I had to take the hood off and crawl up on top of the engine to pry the connection from the bracket. It should pry off with a screwdriver or something. I did end up cutting my hands a decent amount but it is doable. That's why I went with the Motorcraft one, I don't want to do it again

 

[PStansberry78]

My 93' has two, I believe both before the catalytic converter. And it's a manual transmission. I can't see any way to easily get to the connector, which sits behind the motor, around where the plug wires tuck behind.

Ugh. I guess for now I'd better go get the truck off the stands. This isn't getting done today at this point.

 

[PStansberry78]

Here's a picture for reference:

You can see the plugs on the left in this picture for reference. It's so far back there I can barely get my hand to it to even grab the wire. And this is only the driver's side plug. I have no idea where the passenger side ends up.

 

[MrShorty]

Yes, that one is a pain to get to, I'm not entirely sure why Ford felt the need to hide the rear O2 sensor plug up behind the engine like that.

It has been awhile, but, as I recall, at least once I came through the wheel well to access that connector. As I recall, the connector is not that far from the #3 spark plug/wire which are also easiest to access through the wheel well. It's still not easy, but I found this angle allowed me to get reasonable grip on the O2 sensor and pull them apart.

 

[FR-425]

Driver side: Drop the starter motor, then you can reach it from the bottom.

Passenger side: take the wheel off to get at it through the wheel well.

 

[PStansberry78]

Yikes. That makes this project considerably more "project-y". LOL.

Thanks for the tips. Guess this will have to wait until next weekend.

 

[Watchman]

My 93 ex has two O2 sensors and I have unplugged and plugged them a couple of times. Take some string and tie them to the new O2 sensors and then drop/feed them back between the engine and firewall. But make sure you install them into the exhaust first before making the plug connection. This way you are not twisting the wires while trying to screw them into the exhaust. I also removed the spark plug coil pack to make it easier to get my hands between the engine and firewall. However, after reading FR-425's post you may want to try that - it looks to be a lot less stretching and grunting.