I'm not a professional mechanic by any stretch of the imagination but I think I've self-diagnosed a vacuum leak in my 2011 Accord EX-L. Some of the lines look a little worse for wear and, after running down this checklist of vacuum leak symptoms, I was able to add a marked decline in performance. With limited knowledge, is a vacuum leak something I can fix DIY or is this an issue I should bring to professionals? I'm trying to save cash any way that I can but a vacuum leak seems like it could get a bit pricey.