1999 Tacoma exhaust system question

I have a 99 3.4L V6 and when looking at the exhaust system, I noticed that the exhaust pipe directly behind the cat is slipped into the cat but it has a flange on it.
I'm pretty sure that someone has messed with the system, can anyone tell me if the cat back should have a bolt on system or a slip on?

 

From the factory it all bolts together.

A truck that old who can say how many systems have been changed.

What ever works I have seen cats welded in.

Whatever works and gets the job done.

 

Thanks a lot for the info.

 

I like the Factory replacements worse case you can replace things far from home!!

No cutting no welding