Oxygen Sensor Size???

[afree]

While removing a failing oxygen sensor on my 1988 Coupe the threads in the mount on the exhaust got pretty "boogered up". I would like to re-tap the exhaust port before installing the new sensor but have had a hard time getting information as to what size tap to use. I have of course tried to reverse engineer the process by trying to find a bolt that would fit the sensor and then of course I could buy the tap based on the bolt size. On the surface one might think this would be easy but I have been to several different hardware stores and none of the bolts (metric or standard) fit correctly.
Using a caliper in appears that the size of the O2 sensor is 11/16 or about 17 milimeters and the thread spacing seems to be about 16 per inch. Can anyone confirm my measurements. This tap size does not seem to be common so I will probably have to order it when I am sure about the size.

 

[Ken]

I'll try to remember to get that info from mine for you Albert. In the meantime, let's bump this back to the top.

 

[bossvette]

I am not sure, but it may be a pipe tap

 

[SPANISHVETTS]

I am not sure, but it may be a pipe tap

Mine is NPT, I am looking at the spare one as I type this.

 

[afree]

First off I would like to thank all the loyal Corvette fans that offered help in solving my problem. In the end it turned out that I was able to use the 18 mm spark plug thread chaser. I had to remove the exhaust (front section) and by patiently easing the chaser into the O2 sensor "bung" hole I was able to clean up the threads and successfully install the replacement sensor.
Thanks again.
Cheers,
Albert
'88 Coupe

 

[KOPBET]

Congratulations, good job! Need TP for your bunghole?

 

[Dave C. '04 Z06]

FYI: If you ever need to replace a bung you can cut it off with a grinder and then buy the bungs from an exhaust shop.

-Dave C.