Can anyone explain to me the physical differences between the california spec and the federal spec y-pipe? I'm not sure how to tell them apart...thank you.

 

locations of the sensors....
you can tell whether your car is fed or cali
by looking at the number of plugs right infron ot yoru engine.. 4 is cali 2 is fed

 

the federal y-pipe itself is slightly longer that extends up on the front manifold. With the stillen y-pipe, it comes with a second piece.

 

I know that, but I'm talking about the pipe itself....the reason I'm asking is because the aftermarket downpipe that came with the y-pipe set(got it from custommaxima.com) has 3 flanges and 3 bolts....whereas the stock front exhaust manifold has 5 flanges and 5 bolts....so it doesn't match up I was like WTF! Someone tell me why this is please!