When I first put my Injen CAI and RMR muffler on and I didnt have my cat back piping when ever I turned it off it made a fart noise and then it would pop. It kinda sucked but it was pretty amusing also when I pulled into a parking lot at the mall or such and someone walking by would accuse everyone around them of farting when it was my car cutting off. I also found that the sound your talking about happens when I hit the gas stopped like the suction sound so its just the same thing in reverse.

 

i think what is happening is that there is a vaccuum inside your intake manifold when the throttle plate is closed. then when you turn off your car, the existing vaccuum continues to suck air around the throttle plate to balance with the outside atmospheric pressure.

 

Think your intakes are loud....geez you should here mine it can be heard from another car on the freeway with their window down man I love it!!!!

 

Should've spent a little extra change and went to your friendly, local dealership, and bought the RMR intake. It comes with a heat shield. I have it and when I turn MY Lancer off it doesn't make any a$$ sounds! The engine just stops all quiet like. But when I'm driving, and I open her up she lets out a screaming growl like hell has just openned up, which I love
Its really fun when some jerk in a Civic comes whining up beside me, thinks he's got something, and then I bestow the wrath of hells fury on him, and all he sees once again is my taillights!! RMR buy it!!!

Fast as fast can be. You'll never catch me!
Anyone that drives a Honda/Acura deserves to be

 

fast as can be huh....in lancer......

 

yeah when i turn my car it makes a couple deep gargley blurps.

 

OH yeah!!!? Well mine hisses

 

nahhh... that's normal...