I just purchased a injen cold air intake and installed it yesterday on my 2004 6MT. After installation I started up the car and there was no noise difference. Even when I drove it there is still no noise difference. I heard that injen is supposed to be throaty, can someone help to tell me if it normal or if there is supposed to be a noise difference. One other thing is at about 3500 rpms and when I shift at high rpm's there is a "ssss" sound for a couple of seconds and then goes away. Please help!!!

Theres not supposed to be that much of a sound diffrence. It does make the hissing noise when I get off the gas. It does sound throaty/louder mostly only at WOT after 3500-4000RPM.

Get on some nice road, get in 2nd or 3rd, and try to put your right foot through the floor of the car. Wait... Wait... don't change gear.... THERE! Hear it now? 4K rpms and up when the throttle is wide open is when you'll hear the treat.

I agree with doogie...loved your movie by the way in Harold and Kumar go to white castle...j/k.

Rev it up passed 4,000 rpm...window down, no radio...and punch it...you should hear a "hissing" noise in between shifts and when you down shift, it'll sound "throaty" as you put it. If you're still not convinced there's any difference, go to your dealer or find someone with a stock 6mt and listen to the stock engine and do the same test.

Enjoy...!

Thanks guys for the information, I just wanted to know if it was normal and it is, so I am happy. Thanks.