o2 sensor thread info & type needed

[bb]

I had bought a set of headers last year for my 2.7 Turbo (they look like BB. What is the threads that the o2 sensor uses, is it standard on all cars? What happenned was that my headers had an o2 sensor on them which I never hooked up. Last night it must have fallen off and now I need to buy another one mostly to fill the hole.
Also, what is an O2 sensor that is reasonably priced that will fit my headers that I can use with an air fuel gauge whenever I hook one up.

thanks
Oscar

[911pcars]

Thread size is M18 x 1.50 which is pretty much universal. If it's not needed, I understand a Toyota truck drain plug has the same thread size.

Most O2 sensors are only accurate around 14.7:1 which is A/F range they're designed for. The most accurate way to monitor A/F ratios is with a wide-band sensor, but these need calibrating electronics that go with them and are relatively $$. One such brand is sold here @ PParts (no affiliation).

If you go with a standard sensor, use either a 3 or 4 wire type (about $50). The extra wires are for additional grounding and heating (makes for more responsive readings). Some guys have used these with adequate results. Don't install a sensor in a non-working system. Deposits will form on the inactive sensor and reduce its ability to "sense". Wait until you can connect a working system.

Sherwood