when i install the apexi n1 muffler in my civic.i really love the deep tone sound of the muffler,well it's not always sound the same everyday,some other day it sound really bad,not smooth and just sound loud.it feel like backpressure building up.

 

Uh.... What are you trying to say? And/or ask?

 

i mean some day the sound is smooth and deep tone,and some day it sound like a old truck.

 

Yeah i can't explain that.. My old fart can exhaust would do that too.

 

get a good sounding exhaust then

 

suppose to sound like that its a loud exhaust,get a stock one if you don't want it to sound loud.