oxygen sensor connection
 

I'm ordering a bursch cat bypass. new gaskets and bolts etc. doing it my self, since its bolt on. my question is, how is the oxygen sensor attached to the bong hole on the bypass. does it unscrew or pull out, or whatever. just need alittle wisdom before i bust a good o2 sensor.
thanks guys and gals:rolleyes:
911 86 3.2

It simply screws in but it can get stuck in there pretty good if it's old.

is it fragile? should i spray a thread breaker before?

If its old, maybe a new one is in order. They do wear and probably should be replaced every 50k miles

I think 60K is the O2 sensor's service interval IIRC.

ok guys now i'm gonna replace the o2 sensor as well, while installing the cat bypass. i have an 86 targa with 3.2, which sensor should i use? one wire, two wire, three wire? whats the difference?

There's only 1 that's actually made specifically for an 86 Carrera. So if you want to replace the wiring and the plug and have it just fit right out of the box, then pay the money to get this one:
Pelican Parts - Product Information: 965-606-126-01-M14

But there's many that should still work for less, however you would have to splice-in the wiring and re-use your old plug. I used a Bosch O2 sensor for an 86 Ford Taurus on mine, that's a pretty common one that works in an 86 Carrera, and it was like $30-something at Autozone.

You need to get one with the same amount of wires. My 89 has 3 wires, probably your 86 does as well. You can get any 3 wire O2 sensor and the Taurus option is a good one. You need to splice the wires but DO NOT solder them. Bosch makes a universal kit that comes with a special splice connector for about 75$.

you'll need a crow's foot wrench or special O2 socket...not so much to get it out, but to install the new one without f'ing up the wires. I can't remember the size, but I went down to Harbor Freight and purchased a cheap, deep socket and used a cutting wheel on a hand grinder to cut a long groove for the wires. Also used a little PB Blaster to loosen up the old one, and a smidge of anti-seize compound when installing the new one.

Go to your local O'Reilly parts store. They will loan you the correct special O2 tool gratis. They just require a refundable deposit.
They keep quite a few seldom used and special tools for this service. Great customer service idea!

very helpful replies as usual. thanks a bunch guys.;)