mandskri
New Member
Just changed the factory Denso Iridium spark plugs to E3 in my 2008 Civic Si. It involves a lot of parts removal to get at the plugs. The ventilation cowl has to be removed which consists of a plastic upper panel and a steel lower panel. The upper panel is attached with three plastic botton tabs (use a good panel puller to avoid damage) and quick release tabs underneath allowing it to be pulled off. Pull the washer fluid tube off the panel to remove from engine bay. The lower panel has five 10-mm bolts and four 12-mm bolts holding it to the body. To remove the black plastic cover on top of the valve cover requires removing two 10-mm caps and two 10-mm bolts. Each spark plug socket is attached with a 10-mm screw, two require an open-ended wrench. It is easier to pull the sockets off the plugs before trying to unplug the wire connectors by pinching the sides close to the wire end. Applied anti-seize compound to the threads before installing the E3's and then torqued them to 14 lb-ft. Reinstalled boots, connected wires, reinstalled plastic cover and ventillation cowl. Not only idles better, but acceleration is smoother. Will keep track of fuel efficiency to see if it improves. Also changed oil to Mobil 1 5W-30 synthetic.