Do the plugs from the V6 work in the L4, and vise versa? Just a plug, right? One of my plugs broke, so I replaced all 6 (different brand). The remaining 5 plugs are all new, barely used. I don't know why they wouldn't work in an L4, but you can buy a single plug for the L4, or a single plug for the V6. It seems to me that plugs come in boxes of 8. I never thought of plugs as being inherently for a certain number of cylinders.