Just wondering what these actually do? Would it be worth fitting a decat one (rcm) before i get my remap?

Any help appreciated.

 

Connect headers to the turbo.

Definitely worth decatting before a remap.



Great diagram for reference.

 

diagram depends on which car you have

Shaun

 

It does, but in terms of identifying what an Up-Pipe is, it's pretty accurate regardless!

The arrangements of Cat's will vary depending on spec, age, etc.

 

thats great help, many thanks

 

you only have a catted up-pipe fitted to new-age 2.0 WRX cars............all classics, STi's of both flavours and 2.5WRX cars never had any restriction

if your planning a change, a correctly designed/sized "Harvey" up-pipe is what your after