I wouldn't see why not, if you can obviously see 2 cats on the exhaust just after the headers.

 

I wouldn't see why not either...I suppose it all depends on where you take your car...the cats within the Y-pipe are just noticeable by a pair of small indentions on either side...you'd have to explain that to them...

 

The problem here is that its not that you need to have two catalysts (on cars that had 2 cats), its that it is illegal to relocate the cats at all. The number really doesnt matter. Just by the nature of how a catalytic convertor works, it needs to be close to the source for quick heatup, and moving it further away from its original location will lead to a longer time until the cats reach a full operating temp. This leads to why shorties can be emmisions legal, because the drivers side cat can stay in the same location, whereas with LTs the cat would be atleast 1.5 feet further down the line. So in the end, there is NO LT that is emissions legal!!! You can pass the sniffer test, but you have the chance of failing the visual.

Chris

 

Aren't the cats on an LS1 about the same place that they would be on an LT1 w/LT's?