Any tips on O2 sensor replacement?

[91LTDProject]

I asked the shop foreman at work today, and he kinda laughed at me and turned the other way. I had suspected that they hadnt been working right for some time, so I got out the graphing scanner. The one on the left bank of cylinders is not working at all, and the one on the right bank is at about 70% of what it should be. Now, mine are the original sensors, and havnt been touched since 1991, so I cant even imagine what kind of hell their gonna give me to get out, plus where thay are located. I've allready ordered new ones for my car, so has anyone got any tips to make things easier. And another question, when you do a header conversion, are the wires on the stock O2sensors long enough, or do you have to extend them? Thanks guys

[gadget73]

You either extend them, or use Mustang O2 sensors which already have longer wires. If you're buying new, get Mustang ones so you can move them later. Just zip tie the extra wire out of the way in the meantime.

Soak the hell out of the sensors with good penetrating lube before you even consider starting. Sometimes it helps to run the car for a minute or so to warm the manifold, but you don't want it so hot you're gonna burn your skin off. There is a special O2 sensor wrench to get in there to remove them. They're kind of in a bad spot, and they'll play hell coming out most likely. Never done a set, so no special advice to offer. Good luck.

[91LTDProject]

I allready ordered stock ones, and it really upsets the parts department when you back out of an order, so it looks like i'm extending them in the future. I'm 100% sure its gonna be hell, it was tight enough just tryin to get the probe from the scanner in there to check them.

[86bbub]

i got stock ones and replaced the stock ones on my 86 last summer, rusted on like hell but a little penetrating oil and an hr of letting the oil sit and they came out just fine with the O2 sensor specific socket

[Enigma]

I did both of mine last year. A few cuss words are definately in order, but not all that bad. After using pentrating oil, I cut the wires off the end, and used a regular box end wrench to loosen them. Threaded the new ones in, and used the special socket to tighten them. I also remember that I had the option of three different lengths of wire to choose from. Stock, medium, and long for future mods. Can't remember if it was from Advanced, or Rockauto.

[91LTDProject]

Managed to get them in, and I managed to get the old ones out without pulling the threads out of the exhauset manifolds. Soaked them in penetrating oil around 9 this morning, and started the job at 5. Left one was in and out in 15 minutes, right one, Major PITA. But those O2 sockets worked great, and the new sensors have dropped my emission numbers signicantly. Thanks for the tips.

[mrltd]

Never had any issues with mine...Lefty loosy, righty tighty...Nice wrench and a hard tap always got 'em out.

[Mercmarquis]

like they said...penatrating oil and some grunt. Torch it up if its really stuck.