Removing Pre-Cats
 

After a lot of reading and homework, I'm still stumped regarding my FB exhaust.

I want to free up some flow and HP while still keeping the air pump and cat.

I know the back-pressure activated 6PORT is connected to the exhaust and I'm worried that hollowing out / replacing the pre-cats or main-cat will change the back-pressure profile, resulting in the 6 port not actuating properly and reducing top end power.

Can anyone make a recommendation or dispel this myth for me? Thank you!
I want to keep the car relatively stock and original so I can get collectors plates. :)

(So visually, hollowing out the precats would look nice, but I'm totally okay with a pipe if it works better, I will just keep the parts I take off incase I need them later).

Thanks!

You can delete the pre-cats as they are just an added function on a warm up phase anyways.
Even if you go to a header you can set the exhaust up with a presilencer that has the split air tube to activate the ports.

Just clarifying, :)

For 13B FB,

So hollowing out the pre cats and then putting them back on, won't cause any back pressure issues and affect the 6 port?

What changes can be made to the exhaust before you need to worry about this 6 port exhaust back pressure problem? Can you increase the ID of the pipes?

I saw that racing beat has a header and nice exhaust set up but I kind of want to keep the "thermal reactor" for emissions and am considering replacing old cat with a new hi-flo one.

Thank you :)

then get a cat with a split air pipe attachment.