wuts difference btw single wall and double wall?
and is magnaflow loud?? tell me everything u guys no about magnaflow... thx..

===== added =====

and.. just getting the muffler without the whole system worth it?
would it decrease the hp? or cause any problems...

o by the way.. my friends got the system.. for.. i-dont-no-brand-muffler and
the orange light for engine problem.. stays up all the time..
but the shop ppl said its b/c the tube got larger and more air flows through... is that true?? cant trust those ppl..