The only purpose of the Honda valve cover gaskets and seals are to contain the engine oil so it cannot leak onto the exterior of the engine. The majority of the valve cover gaskets are now made of a high quality polymer, but in time will wear out due to heat related stress. The importance of the valve cover gaskets and spark plug seals is that they are located on the upper portion of the Honda engine. If any one of them has a leak in it, the oil will run down the entire engine cause it to not only look bad, but makes it possible for more dirt and debris to adhere to the exterior of the Honda engine. Since the new engines are so sensitive to foreign objects because of all the sensors and wiring, this dirt can cause interference with the data they are acquiring. The replacement of the valve cover gaskets has become more complex with the newer Honda engines, but is still a procedure most owners can do themselves. The most critical part of this procedure is the remembering of where everything goes that is taken off and the order in which it was removed. The most critical part of replacing the old valve cover gasket and seals is the removal of all of the old material along with any oil that might be present on the surfaces of the contact areas. If this is not done, then a new leak of oil will occur. Once the new Honda valve cover gasket and seals are in place, the engine will look as good as it performs. This will make any owner proud to raise their hood.