o2 sensor plug needed

[gherndon at eyeontech.com (George Herndon)]

gordon,

an 18 x YY sounds about right as that's the same or slightly larger 
than my expected 3/4" fitting.  i'll check into it when i'm at the 
parts store later today and report back.  i should also check my tap 
and die set.  i'm not sure i have a tap that large, but i may.

-george


On Oct 4, 2004, at 10:15 AM, Gordon Forbess wrote:

> On Mon, 4 Oct 2004 10:04:14 -0400, George Herndon
> <gherndon@eyeontech.com> wrote:
>
>> i installed my new TT 2.25" exhaust this weekend, replacing the ansa
>> model that was not emissions compliant here in NC.
>>
>> my car is a '78 with a race header that is a 4 into 1 design with a
>> bung for an o2 sensor located near the flex joint and cat (unknown
>> design).  a visual inspection of the opening shows a fine threaded nut
>> in the 3/4" range. my calipers say ~ .74
>>
>> the autoparts store has bosch o2 sensors for an '81 and it looks to
>> have course threads.
>>
>> can anyone shed light on if they've ever encountered a fine threaded 
>> o2
>> sensor bung?
>>
>> ideally, i'd like to plug it, in case i need an o2 sensor in the
>> future.  i could always weld it closed and forget it.
>
> To plug the O2 sensor hole in my header I used an aftermarket oil
> drain plug I found at a FLAPS.  18 X 1.5 thread, I think.
>
> Gordon
>
> 75 Mk I/Drake 1.9
> http://pws.prserv.net/gforbess/scirocco/scirocco.htm