One of my older sites that I've admittedly neglected of late got hammered with the Bourbon update, then with the latest PR update, I noticed all but the main page had dropped to PR 0. Since it's getting next to no traffic from Google, I assume this means it's penalized. I went into my links pages (when I first got started two years ago, I was a somewhat indiscriminate link exchanger), I found links to three or four older sites that are now PR 0. Based on that (and the fact that content wasn't hot anyway), I deleted the links.
My question is: do you think this could by why my site was penalized in the first place, and will my traffic and PR come back eventually on its own or do I need to do something more proactive? (And if so, what?)