I have a couple missing from my car, what does it do and we really need them?

 

I'm pretty sure they're heat shields to protect the wire boots though there may be another reason and to me they seem to get in the way all the time.
David

 

you don't need them but they can be useful. by pulling on the metal covers you prevent breaking your spark plug wire. If you pull on the wire, chances are it will break,

If you choose not to use them, just remember to pull on the wire boot not the wire

 

If your using aftermarket high temp spark plug leads you don't need them.

 

If your using stock wires, use the shields!

 

You really only need them on the #1 and #3 plugs , these are the plugs on the side of the EGR valve . But , if you have all but 2 , you might as well use the ones you have .

 

I don't use them anymore since I lost one of them and my car runs fine.

 

If you have QUALITY Aftermarket wires you don't need them.

 

I think they might be some kind of radio interference shield, because I don't see how they'd protect the boots from getting melted. If that were the case, every car woudl have 'em. But I didn't see any difference, melt-wise or radio-static-wise, after pulling them back in '94- even before using MSD wires. Found one in the girlfri..uh...fiance's 4th gen, wedged underneath the hood latch. It's the only one she's got on that car... none of 'em were on the plug boots.