Catalytic Converters 2003/2004
 

Hey guys I have a question that I need help with. I love cars, am mechanically minded but, don't know very much when it comes to performance etc.

I recently had a Gemballa exhaust installed on my 2003 2.7. In Australia we only have one set of cats after the back box connected to the 'U' bends (lucky us). My question is related to the catalytic converters for the 03/04 models, which I believe there was a change - is there a pipe diameter size difference between the 'S' and non-S models?
I ask as the 'U' pipes had to be modified (reduced) to sleeve together with the cat converters on my non-s model (2.7L).

Now, having said that and if it is the case that the size is different, am I better off getting 'S' model cats to fit to my car (and having new or reshaped 'U' bends back to the original size) so that the flow works better?

I am not looking to buy 200 cell cats at this stage plus the exhaust is pretty loud as it is!


A real technical insight into this and a knowledge of any changes in the 03/04 models would be great.

Thanks, I look forward to some feedback.

I am pretty sure all the Aussie & ROW 986 exhaust systems are the same except for the muffler outlet tip. I am more sure it would not be worth the hassle & expense to change the secondary cats. If anything change the manifolds that bolt to the engine to SMALL tube headers for a high rpm power gain & no louder than it is now. Check the part number for Catalytic converters for 99-2003 ROW & see if they are all the same.

I would agree as well. It's a small risk to take. And I'm sure you'll learn something from trying it first. Listen to BYprodriver, I do yearn for his advice.