Well I am in the middle of the downpipe project. The problem, the studs on the main cat, broken off and won't screw out. So I cut them off, and decided to drill through them. Well that isn't happening, they are fairly tough and the whole exhaust system moves too much, so what I guess I am going to have to do is take it off. What do I take off? There is a line that looks like it runs to the main cat, what is it? Also I have a hole in my muffler so I need to replace it, so why not buy an exhaust system. Will I be alright getting an exhaust with an apexi intake and downpipe or do I have to have a boost controller?

 

You'll need a boost controller, search here for "Home Depot boost controller" and you'll be fine. The line that runs into the main cat is from your air pump. It gives the cat oxygen to combust the fuel in the exhaust.

Taking the main cat and cat back exhaust off are a lot easier than replacing the downpipe so if you decided to DIY the downpipe install the rest of it should be "easy"

 

make a ball and spring type controller, much better then jsut the bleeder valve which does work to some extent

 

make a ball and spring type controller, much better then jsut the bleeder valve which does work to some extent

 

make a ball and spring type controller, much better then jsut the bleeder valve which does work to some extent

 

make a ball and spring type controller, much better then jsut the bleeder valve which does work to some extent