A few weeks ago I got Magnaflow dual exhaust put on. I have had really bad vibrating since they have been on. When I am idling it vibrates so bad it makes my hand shake when it's on the steering wheel. Also, around 40-45 I get a really high pitched almost whistle like noise. Does anybody have any idea what either of these things is from? I took it back to the exhaust shop and they spent hours looking at it and they said the exhaust isn't touching anything and the hangers are fine. They put a 8in flex pipe on it thinking that might fix it, but it didn't. They had no idea what it might be and said to try driving it for a while to see if that fixes it, but it hasn't. They can't seem to figure out the problem and neither can my dad. Anybody have any ideas what it might be? It's really embarrassing cause you can hear it outside vibrating too.