I am trying to get the correct size tap and die for my autometer pyrometer egt sensor i have been to home depot and this thing does not thread into any of their test threaders, I have that 37 piece tap and die craftsman metric thingy and nothing seams to fit. does anyone have any info on the specific tap size that will work drilling through the downpipe?

I have attached a pic

 

Thats because most sets only include 1/8" NPT taps. Hard to tell, but looks like a 1/4" NPT fitting. Go to an actually bolt/industrial/hardware store and they should have it. You'll have a hard time finding those at Sears, Lowes, and Home Depot.

 

If my memory serves me right, the thread pitch is 1/8" NTP.

On another note. I personally would weld a egt bung in the down pipe and install the probe in that. I feel that will cause less issues i.e ,leaks, mis-thread in the long run.

 

here is what I am talking about:

http://tscsensors.com/bngad0000000180weldb.html