Had a misfire issue, and this time I wanted to see if I could check the COPs instead of swapping them out.

I have bought the 76564 COP Interceptor, and after some playing around with it, was able to see an anomaly with one of the cops, changed that one, and problem solved.

Not sure if you will always be able to pick it out, but I would guess you have a good chance.

Its relatively cheap, and basically can pay itself more or less, as you only need to buy a cop for the failed one.