Ever since I had a y-pipe installed on my 3rd gen there have been creaking noises from the engine bay... Anyone know what this is? Happened to my buddys 4th gen too.

 

i had that too, but it went away after about a month. i first thought it was the flex section, but after i looked under my car i noticed it was kinda close to the cross member, so perhaps that had something to do with it. i didnt do anything thought and it went away

 

Same thing here... some 5th gen members told me to put some washers where the cross member is to reduce noise. Haven't tried it yet. They also said I can remove it.