Would You Trust These New Champion Spark Plugs?

Mike69cuda said

This one tests the ignition system, does it also test plugs?

Click to expand...

if you want to actually test a plug, you'll need to pull it.

the tester that YY1 is good if you don't want to pull them.

the old: laying it up on ground will tell you if it's firing, but it won't tell you if it's firing under compression. (as mopar leo outlined above)