I had a off road mac h-pipe put on last week. After the car sits for some time I start it up and I get a couple of drops out of one of the connections towards the back. The cars sounds good But there is a little hiss sometimes. some say it is the stainless steel sound from the remaining exhaust or the air moving through the pipes. I think if condesation is leaking then I would think exhaust gas is also leaking out too. I need some suggestions. I have had all the bolts retorqued. what should I do?