WTF type problem

[Sydcad]

A couple of years ago ( 2-1/2 ) to be exact my '09 caddy started misfiring. I took it to a local VW mechanic as I didn't know whether it was a spark plug or lead playing up. He diagnosed the fault as no.1 lead and replaced all leads and spark plugs. The plugs were long overdue and I thought it better to replace all the leads anyway but now I have the same problem on no.3 and this time the lead is live. If you try to touch it with the engine running you get zapped. WTF.
I removed the lead obviously with the engine off and checked for breaks in it but can't see any. I checked the resistance and it reads 5.75k instead of 5k. I don't know if the slight increase is critical or not and whether there could be something else wrong causing the lead to be live. Anybody had this issue and where's a good place to buy a single lead. Actually I know of one place but they want $55. I can buy a full set for $132 so want a better deal. In Sydney btw.

[feenix74]

Many years ago I had a similar problem with leads on my 97 Golf. It was misfiring, I changed the sparkplugs, still misfired, I checked the leads and I was getting zapped on all four leads but was able to confirm that it was cylinder 3 that was the problem. I took it up to my VW specialist mechanic and a new set of leads fixed the problem.

I get the impression the extra resistance or the partial break means that the sparkplug is not getting enough zap to fire properly. At the time, I did quiz my mechanic whether it was worthwhile just replacing the one lead, he indicated that it was always better to replace the entire set (and yes my VW specialist mechanic has proven themselves trustworthy over the last 15+ years).

[Sydcad]

ahh ok so it happens. I've never heard of a lead going live b4 but it's a quick way to find out which one is faulty. I thought last time it was better to replace them all but since they didn't last long I want to try and replace a single lead but that seems to be very difficult to find unless I want to get my pants pulled down and my pockets emptied which I don't