How can you tell by pysically looking at the Exhaust if it a de-cat or not? And without taken it off. I have a Kakimoto Racing Exhaust with 3" I think. Because it's dam big . The pipe work I'm talking about

Chris

 

Are there any bulges in the pipe work?
If not than good chance its a de-cat.

 

Here some photo's

 

that looks like a center section CAT

 

Might be a cat but my money would be on a centre resonator. It keeps the rumble down therefore meeting noise regs on track. Easiest way to find out is take it off and have a look inside, if you can see through it then it ain't no cat,

Looks like you have the standard catted downpipe though

Most after market racing exhuast don't have catted sections normally only the down pipe which would have a 100 cell sports cat