so i been planning on purchasing a toda header for my em1. my car has an apexi ws2 exhaust with a stock catalytic converter. the toda header requires either a 63.5mm (2.5inch) catalytic converter or a test pipe. id like to cut the test pipe out of thought since its illegal, and i want to keep everything on the car up to spec. a buddy at my work told me i could upgrade my converter to a magnaflow high flow converter, but i have no clue if that would even sound good. what do you guys think? are there any other things i could, other catalytic converters i could put on to get this header in.

 

the difference between cat and test pipe is notable(sound/performance wise) the difference between a hi-flow-cat and regular cat...not really. if you had a straight pipe you would notice sound wise(trust me). go with the high flow over all it will be you'r best bet if you want to stay within emishion limits.(if they exist where you live)

 

exactly, the ws2 exhaust is so quiet, and i love it so thats another reason a test pipe is off my options. do you have any clue if a magnaflow cat would go well with the ws2 exhaust being that the ws2 is such a quiet sound.

anyone have a WS2 with a high flow cat, or atleast 2.5 inch.

 

if you'r upgrading to a high flow cat(over stock) then no there won't be any sound increse. im my case i have an almost gutted car so i notice the pebles hitting the weel weel.... you should be fine if you don't want it louder.