I have a 99 GSR and everytime i hit 3500 RPM's it makes the most annoying rattle ever. I tried searching and only found out that the problem was common but no one ever clearly diagnosed the problem. For some it was the heat shield around that cat, the cat itself was broken and something inside was rattling or it was the exhausts A-Pipe. So i was thinking of just getting a new header and cat since i wanted to do this anyways. Now my question is, will my friends 01 ITR header bolt on to my 99 GSR without any fabrication or mounting issues ? Thanks

 

my header did the same, the noise was jus comin form the header it self, i got dc header now, problem solved