im pretty sure the tensioner is much of a problem to replace, ive only done it on a sohc/ and dohc civic. prelude motor shouldnt be to much harder. actually now that i think of it, i thin its under the timing cover. you can tighten and loosen it without removing the cover, but to completely remove it im sure your going to have to take the cover off. to adjust there should be a removable plug on the cover to get to the bolt the loosens it and i cant remember how you add or loosen the tension. im pretty rusty probably need to wait on another reply, ive been out of working on honda's since i joined the airforce, (over a year ago) its pissing me off. i think im going to go volunteer at the honda dealorship this weekend