Engine misfires, runs rough, stalls unexpectly, no failure code on Buick Lucerne

Average mileage: 85,333 (36,000–120,000)
Engines affected: 3.8L V6, 4.6L V8
2 model years affected: 2006, 2008
3 people reported this problem
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Viewing 1 - 2 of 2 problem details
2008 Buick Lucerne - 3.8L V6 36,000 mi,
Car would begin to misfire, run rough, and stall after being driven for awhile. Sometimes door locks would chatter or other odd electrical problems. Poor connection of main harness into distribution box beneath the back seat. Replace connector and distribution box. Warning: Unburnt fuel in exhaust from initial problem will lead to catalytic converter failure.
2008 Buick Lucerne - 3.8L V6 120,000 mi,
Mis fired and stalled just out of blue. No warn signs or even engine light. Cause was cracked ingnition coils which in turn burn out ingnition module and in turn the misfiring let large amount of gas into catalytic convert plugging it and causing engine not to run pass an ideal