Sail Hatan

I was under the impression that all ls1 f body's had that weird y pipe
With the flat part in it. I just got some pulling mine out and it's
All 2 1/2 , and has a nice merge, and no flat portion. My friends
02 tA had the flat one, was mine replaced? It was bolted up to the stock manifolds/cats.

Also, why are they called cat back exhaust in an ls1 if the cats are before the y pipe?

Sail Hatan

I'll get some pics up when I get home.

BigBirdLS1

You definitely had an aftermarket y-pipe. And its called cat-back exhaust because you replace from the "cat" backwards.

Sail Hatan

I understand why it's a cat back, but normal cars are manifolds>y pipe>cats>cat back. That's not the case with ls1 cars, manifolds>cats>y pipe> "cat back"

BigBirdLS1

Im gonna go out on a limb and speculate that the y-pipe and cat configuration is because of ground clearance. Cats are pretty big around and the whole why the factory y-pipe is flat i because of ground clearance. That is just a guess though.

BigBirdLS1

I'm also gonna say the reason might be because alot of engines only need 1 cat to pass emission regulations and sound regulations. Whereas the LS1 might have needed two for that purpose and the stock exhaust configuration is the only way to do it. Again just a guess

jimmyblue

iTrader: (11)

SLP Y has a nice merge and is entirely round. It's a
stainless that turns brown with age (409?).

BigBirdLS1

Being OP has a T/A it wouldn't have had the SLP option for the exhaust right?

jimmyblue

iTrader: (11)

The SLP Y is aftermarket, not OE / SLP installed, and has
no relation to the dealer options.

Sail Hatan

I'll get a picture up. The drivers side is cut
And the passenger side is not. With a little work it could work on long tubes. It looks like rusty steel but I could be wrong. I also have the lm1, is that whole thing stainless?

TransAmWS.6

Yes, the LM1 is a stainless steel catback

NVR_SPDS

iTrader: (39)

Sounds like my SLP Y pipe. I have the same combo, SLP Y and LM1

Sail Hatan

Here it is. The right side of the pic was the drivers side tube which was cut.

NVR_SPDS

iTrader: (39)

Thats the SLP Y pipe.

Sail Hatan

That's interesting. Thanks guys! Well now it sits in the yard lol.