Hello fellow Vibers....
I have an '09 GT with roughly 90,000 miles. I recently developed an loud rattle/grinding noise at around 1500 RPM. The noise sounds like a loose heat shield but much louder and only at around 1500 RPM both accelerating and decelerating. A friend of mine suggested that the catalytic converter internals may have let loose. That is an expensive fix only to not be the issue. I haven't had a chance to have a professional look at it, so I thought I would ask some Vibe enthusiasts instead. Any suggestions would be helpful. Thanks!!