Hi everyone just got a honda accord and doing some maintence and was gunna do an ignition tune up and already ordered my plugs and got spark plugs and now getting the cap and rotor and ik the reason behind the rotor being replaced but do u need to replace the cap really amd if so why espically if u put a new gasket on just wondering and i can understand if corrosion but was just looking on some info as to why thanks guys

 

Should replace cap and rotor at the same time. They wear together. The rotor can wear and scrape the cap and the little internal terminals.

 

I can only see this happening if the rotor snaps and bounces around in the cap. Other than that, it really cant touch the cap. The wear is on the metal plate sandwiched in the rotor that deteriorates and carbons up

The cap has a contact button that touched the top of the rotor to transfer the energy/spark. It's a wear item and at some point it wears out and the spark then has to arc to the rotor and then to the posts. That can be problematic.

The 4 posts are also wear items but quite often they are still good if the cap is OEM and you just have to scrape the white carbon buildup off of them.

Both parts wear and after some time will cause miss firing. It is good practice to replace both when you decide it's time to replace.