I just installed the stillen universal Y pipe on my '96 GLE, I don't hear any difference when i turn on the car, but when i accelerate, i hear a hissing sound that gets increasingly louder the more gas i give it, is this i leak? or are there any other ways to check?

 

I just installed a Cattman Y on my 2k1. And I hear the exact same thing....talked to others and that is just the sound characterstic it gives. Are you feeling significant power gains since stock?

 

honestly....not huge gains, ya it pulls a little more but i kinda expected to feel a little bit more power out of it...oh well.

 

Aw common i was hoping that someone could help me out here....maybe i should be noticing more gains but i'm not cuz there is a leak, or maybe i was just expecting more...is there any real way for me to know based on noise? help me out here guys

 

its normal...