Okay, I did a valve cover change because my drivers side valve cover gasket was leaking (03 350z)...so I replaced that and put everything back together and hooked everything back up, and now my car idels real bad as if my spark plugs went bad. But they were working fine before the valve cover change. I replaced the spark plugs on the drivers side for today and put in a new air filter and it still idels hard...so tomorrow im doing the passenger side spark plugs and hopefully that fixes it but any comments, tips, or suggestions would be appreciate!

 

Check that you put all the vac hoses back on especially the one on the upper intake post maf.