Cat-forward Question

[Runnin'OnEmpty]

I was under my X over the weekend changing oil for the first time, and was looking at the cats. There's a total of four; one small cat on each header pipe, and two more after the pipes connect. And one HUGE muffler. The thing is, even with all the cats and big muffler, the stock exhaust isn't all that quiet.

When you install a high-flow cat on these systems, what do you do with the two small header cats? And do you replace the other two stock cats with one high-flow?

I plan on doing some exhaust mods eventually, but I want to do them right, and don't want to set off the MIL.
Thanks for any opinions.

 

[Alec]

The way to do it on that quad setup is to get 2 parallel high-flow cats. I only had 2 inline cats on mine, so I just replaced them with one.