I use to have th n1 on a civic hatch, and I had the same prob that you are having. All I did to resolve that problem was I made sure that all the tubing was aligned right before you tighten it, cause it does come with some slack.

-Alex

PS: Be very careful, cause it hangs too low. By the time I sold mine it had a lot of big gash looking dents which made it sound like crap.