If youre willing to work hard. AP Physics B tests general knowledge of a wide range of subjects, so you might have to go faster than your honors physics class. What are you up to now?
There are some things to consider. If you take the AP test this May, that doesn't leave you nearly enough time to prepare, in my opinion. Although I took AP Physics C, I don't know much about the B test. And if you spend $80 on the test, you better be sure an appropriate lower score can get you any credit at the universities you're thinking of attending.
everything is possible. Hey, I self studied chem AP and computer science AB when I was in high school. If you focus on physics, you can do it!
(make sure to get some books though... get a barons, princeton review or something like that for self-studying... do every problem in the exercise, and you shall be fine)
I self-studied both AP Physics C tests (mechanics + E&M) and a couple more AP's also...and I did get 5's on them, so it's possible. It depends on how comfortable you already feel with the material, how disciplined with the self-studying you are, and how much experience you have with self-study.
Make sure you get a good physics textbook, but also, get a really good set of AP physics study guides (especially the Barron's)