Need to replace the studs / bolts for the connections at the rear cats.

Purchased a Walker CAT and it did not come with studs / bolts to connect to the manifold or the rear cat.
To make room for the new Walker, I had to unbolts the rear CAT connection to the rear exhaust. When I did this, the stud threads are gone.

Oddly when I went to removed the old nuts,
: all nuts for the front cat (at manifold and rear CAT connections) were 14mm
: the nuts at the rear cat to the mid-pipe/muffler were 15MM.

Nissan Front Nuts (Front CAT to rear CAT) are 20602-41G00
Nissan Rear Nuts (rear CAT to muffler ) are 08918-3401A

Would like to source these nuts and bolts away from dealer, and need to know the stud specs.
I think all the studs are M10-1.25? Fine Thread.

Can anyone confirm this please?

The two different parts numbers, and the 14mm vs 15mm socket use, has me puzzled.

Thanks for your help.

Well, no reason for a follow up.

Bought the nuts for the rear cats and they are 14MM. Looks like whoever replaced the muffler system before I bought the Patty just put on 15MM.

Get this. Paid $8.94 CND, for each replacement catalytic converter nut. I"m going to write the dealership as that is price gouging.

Nissan usually uses even-numbered sizes up to 14MM and then odd-numbered sizes starting at 17MM. US domestics seem to be the opposite, using odd-numbered sizes up to 15MM and then even-numbered sizes, starting at 16MM. Unless you had an old Chrysler with a Mitsubishi engine, then you had every size under the sun! I never understood the reasoning nor why they couldn't have been more standardized in sizing, but it is what it is! Even worse: European vehicles!
When I changed out my upstream converter with a Walker Ultra and replaced the rear cats with DT mid-pipes, I went to my local Lowes hardware store and purchased the 10MM hardware. A lot cheaper than the genuine Nissan hardware and no shipping costs!