I haven't taken the pcat yet, but I had a similar question and everyone I talked to recommended taking at least gen chem II first, and that there are a few ochem questions, but not enough for it to be abolutely necessary to do it first.
Hope that helps.
There is no need to study Organic Chemistry for the PCAT. You only need to be able to recognize the different families (ex. Esters + Ketones). Study up on general chemistry and forget everything you ever learned about O-chem!