I'm putting an ls6 in my 77 vette which I still have to smog in ca, and was wondering how far back you can place the cat and still have it function properly, also since I can't switch over to a true dual exhaust I was thinking of using the cat as sort of an x pipe with a y pipe going into it and a y pipe coming out into dual borla xr-1 bullets... any thoughts would be appreciated, and I'd rather not swap exhaust systems to get it smogged cuz money is a lil tight to get dual systems and swap everything before the smog...

 

cali. has some hyper strict rules about cat placement, you better call the B.A.R. before you spend a ton of cash, or worse yet, listen to someone on this board tell you that it doesn't matter.

 

you cant do **** in Cali... that place blows.

 

in Cali you HAVE to have the cats in the stock position AND high flows usually won't pass. I'd take your car to a certified muffler shop and have them do it honestly, because they will most likely do it legally so you are able to pass smog

Ca sucks

 

Quoted for truth.

However, the LS6 is a ULEV engine, so assuming you get the cats done up right, emissions shouldn't be a problem at all.