yes unfortunatly Mazda thought that it was a good idea for the ECU have a learning curve to it, so you will have to tune your car almost immediatly (spelled wrong dont care)

 

anyways its a 4 inch exhaust, is that the same as yours?, hopefully they dyno test it so i can see the improvements. there is like one cop in my town and he is a state cop, so hes not around much

 

4in mines gonna be either 2.5 or 3.5in

 

a 4inch exhaust on a non-turbo motor is WAY to big, you will lose much bottom end power/torque and probably wont gain anything. the most you should go, on a non turbo motor, would be 2.5inch. Actually Magnaflow did a nice write up about exhaust sizes for different motor displacements. here is a little FAQ about pipe size from Magnaflow.

http://www.magnaflow.com/07techtips/faq/question10.asp

 

i had a feeling 4in was too big

 

3.5inch is to large as well.

 

i had a feeling that 3.5in was stretching also...ive made up mind ill have a.....20in pipe sike, 2.5in will be fine.

 

i even ordered it right out of a place that does exhausts, hmmm bastards, i'll see if i heard wrong, is there a standard size exhaust magnaflow makes for mazda? maybe they ordered that

 

that is an unknown to me but just ask or demand that it be 2.5in

 

i read it wrong, here is the part # i gave the guy

http://www.magnaflow.com/02product/parts/15861_lg.jpg