Popping noise??

[anoobie]

Hi everyone.
I put the loud magnaflow cat-back system on my 09 g8 gt and i have a popping noise when i let off the throttle in the active select mode. When the engine is holding back it pops a few times when i downshift. I was just wondering if this is normal for this system or if I might have a small leak? I like to drive in active select mode so it stays in v-8 mode, sounds better .
This is the first car i've had that I had to use the cruise control to keep from speeding.Awesome!!!!!!!

[LazMan]

I am a terror in my new GXP as far as speeding goes. It pops between shifts with the stock exhaust, just as you describe on your GT.

[g-wizzelwhat]

what you are experiencing on the gt is a lack of back pressure and will eventually cause the vavle seats to "burn" then you will lose compression, but that may not happen for a few years. all that is happening is when you let off the throttle the raw unspent fuel if being dumped in to the header/ exhaust mainfold and igniting there. if you were to have the car tuned it may help or find a way to add some back pressure to the exhaust system. as for the gxp if it is still stock you may want to have that looked at.