Presently I have a 90 2.5 wrangler. I have heard of some people taking the restrictors(?) out and putting a K&N filter in for improved performance and economy. I am new to wranglers so I was wondering if anybody knows what is involved with removing them. Would it be worth it to do that without getting a K&N? Would it be worth it at all? Any other suggestions? Just trying to look for "cheap" improvements, if there is such a thing!