alright so for the past coupel of months i've had this weird noise from the bottom of my car, i redid my whole exhaust and it's still there, so it was the ol dand new system,. When ever i give it gas or accelerate on city streets i hear a sound liek a (szzszszszszsz) very weird noise, and only under acceleration, also very noticable when on highway. I looked at my heat shields going down the sdtraight pipe, and they were loose. I fixed them up and they are on there tight so it's not from that. I knwo that all my bolts are also tight that connect the felx to the cat and so forth. When i start the car and get under it i can;'t hear it but after it's warmed up , i get out and hear a soudn of air escaping, and first it sounds from the back end, but when you stick your head under it sounds liek it's comming ffrom the flex pipe. I have had this for a little bit now and it woudl be nioce to get rid of. I have the next 2 days off so i want to take care of it. Has anyone had these problem before? I tried to be very specific with it, and sorry if anything is mispelled, i don't care tonight.