I tried that belt conditioner crap, which is actually crap because it just made the belt squeak even worse
I've done a search and basically it hasn't helped because obviously there is a bunch of things that could cause it. Belt too tight, too lose, tensioner, idler, smog, etc.
I never had a problem running the shorter belt until recently so I don't believe the size is wrong. I also checked my pullies to see if anyone were loose. The idler seemed to move a tiny bit side to side.
Its just hard to diagnose any car issues when I'm not supposed to work on my car in my apartment complex.
Any suggestions would be great.
EDIT: forgot to mention I have ASP underdrive pullies and the belt is from advanced auto