on my 94 gsr it is making rattling and knocking noise that sounds like it is coming from around in front of my resinator and it virbrates in my car around my feet. It does in low rpms and sometimes at idle, it doesnt do it all the time...i am wondering if anyone knows what it could be, it started happending after i back into this grass hill that pushed back my exhaust ( i dont know if this has to do with it) thanks for the help?

 

it's prolly your exhaust piping..put it on a lift or bring it up..it's probably rubbing against the rear sway bar..take a pry bar and move it over slightly...

 

Sounds like the heat shields around the cat, or maybe even around the header, if you've got the stock one still on.