Hello, I am new and confused and also not car savvy so please bear with me!
I have a 2004 Subaru outback that has transmission issues. The check engine/cruise control lights are on all the time and I've been told by the previous owner (my parents lol) that it needs a new catalytic convertor. I've had this car for about 8 months and it drives great despite the impending engine issues. However, over the past month I have been hearing this vibration-like sound near the driver's side front wheel well that just sounds like metal on metal at exactly 175 rpm. It only happens on acceleration and is not turning-dependent nor does it affect the steering wheel or driving whatsoever. It's just a loud friction noise at relatively low speeds.
I should note that I had a look at it to try and diagnose the issue and all the basic hardware underneath is tightened and it is not the same sound of a bad CV axle that I've been listening to all over Youtube
Also, if anyone wants to tackle my transmission problem that would be useful, I find it hard to believe my car runs this great (responsive engine/never overheats) when I've been told the catalytic converter needs replaced.