2.5 Engine= JUNK!!!
If adding the extra length doesn't accomplish anything as you say it wouldn't, then why are so many people solving, or at least drastically reducing the problem by adding the extra pressure line? It has drastically reduced the problem on my Maxx, and I've heard of people completely resolving this issue with the extra line. I can tell you it isn't a problem you're going to get rid of with tuning. I spent countless hours trying to get rid of it tuning mine, and it can't be tuned away. The extra pressure line definitely helps.