im trying to get some info on how much my exaust system will cost and im wondering if when im looking for a catalatic converter if i have to look for a brand to match the y - pipe and/or the rest of the exhaust or just match up flange sizes ??? and is a high flow cat really neccassary for a car that makes less than 300 hp ??

 

Cats that are universal require some fab work. Whether that is a slip fit that needs to be welded or addition of a flange. If you get a full 3" exhaust tailiroed to TPI cars you can get a direct fit cat that will bolt in between with almost no fab work. However that comes with a cost and can be the differece between $150 and $30. Even with less than 300 hp a high flow cat is a nice upgrade.