2002 Chevy Silverado Ignition Coil

No real good way to test, you measure primary and secondary resistance.

If you have a miss, move coil to another position, if miss follows, coil is bad.

Hi,

You can test coils with an ohm meter, but that is a waste of time - they can test good but still be bad.
I just replaced all 3 coils on an '02 V6 Camaro. One or two were definitely bad. I only replaced the third because they were cheap enough and I wanted more peace of mind. Found mine CHEAP on eBay,
brand new and OE too. They are easy enough to replace, you might try getting a whole new set if you can find them cheap enough, otherwise, just buy 4, chances are you don't have 4 bad ones, but you will have a spare in case of future trouble.

If you have a coil on each cylinder, it may be worth a trip to dealer, they can test coil output with there scanners, but the individual coils are expensive for these types.

Sorry, but all due respect to prince, I wouldn't trust a dealer mechanic to tell me which coil out of 8 is bad. I've had TOO MANY bad experiences with dealerships to go this route, unless you have a REALLY GOOD relationship with a long time dealer. They aren't in the business these days of fixing it right the first time and giving you the lowest possible bill, trust me.

I'll bet that individual coils don't cost very much, especially if you buy them from the internet. I bought **3** coils for a V6 Camaro for $60, including shipping, from eBay. They were brand new,
OE, and worked GREAT. My car now runs like brand new. My coils fired 2 cylinders for each coil. If I had bought them from a local parts store, I'm sure that I would have spent at least $150, PLUS sales taxes.
Consider that.

Well you have to find an honest dealer or garage, not impossible.