k, i have an 06 mazda 6i. 160 hp stock, 5 speed. i have a cai, i DO NOT have a full exhaust, took it to my mechanic and one from midas. they both told me i didnt need it because the setup on it was already kickass. i think its 2.25 all the way back already, not sure. but i trusted them. what i did do was, get2 magnaflow mufflers. its dual exhuast. so they cut it off bout 2 feet behind the actual muffler, u know where it bolts up? neways, someone told me to get 2 high flow cats? yes, no? what? is it gonna do anything? someone also told me to change my midpipe? wouldnt that be like getting cat-back exhause. neways im confused. wana add hp. but they dont make s*** for my car yet. pleasee wb.
hi-flow cats!?!?! WRITE BACK!!!
- Thread starter rainmen
- Start date
usually the most restrictive part of a stock exhaust system is the cat not the muffler. Changing to a high flow muffler is a good step. The next one should be high flow cats. The best thing you can do for a motor is air-in and air-out. You already have the CAI so air-in is covered(unless you want to spring for a turbo) 
. Now you need to get the air-out and that comes from a straight pipe with the least restriction possible in the cat(s) and muffler(s). Now you can't have a straight pipe is has to bend around the undercarriage of the car, but the high flow cat(s) will help a lot. If the 6i is a 4cyl. then you should only have one (1) cat but I don't know this for sure, somebody correct me if I'm wrong.
. Now you need to get the air-out and that comes from a straight pipe with the least restriction possible in the cat(s) and muffler(s). Now you can't have a straight pipe is has to bend around the undercarriage of the car, but the high flow cat(s) will help a lot. If the 6i is a 4cyl. then you should only have one (1) cat but I don't know this for sure, somebody correct me if I'm wrong.
