Tell us what TL you have, 2.5 TL presumably since you said singular "valve cover", but humor us w/ the info.
Generally valve cover gasket and spark plug tube seals will do the job. On 2.5TL, the space to reinstall cover w/o disturburbing the gasket in the cover is limited.
2006 Acura TSX, 2010 Acura TSX
2005 Toyota Matrix, 1994 Honda Accord
2003 Acura MDX
I don't drive em, just fix em.