what are the descriptions of a failed coil pack
No spark or weak spark on that bank of plugs, 02 Deville with a Northstar even if one fails to fire the whole pack must be replaced.
The engine can run rough or have misfiring.when the coil pack has a partial failure. The most basic scan tool will detect this most auto supply stores do this for no fee ..except in California were its illegal for them to scan a car there!
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