i just recently changed my old beat obd1 ls valve cover for a obd2 valve cover. I didn't do it for any nostalgic or brownie points with the local tuners but for a more clean and better look (for me). Plus my old one had oil all over and the paint was chipping, it was oogley! My question is if anyone seen the obd2 valve covers there is a hole on the top near the intake manifold. Is it safe to leave it open or should i stick a little filter in there? I don't want something to fall in and ruin ma sheet so im trying to take as many precautions as i can. Any suggestions or comments are welcome.