Best Answer

Could be,

spark plug(s),

contaminated fuel (water),

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โˆ™ 2014-10-31 18:48:55
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Q: What might cause a sporadic misfire on a 99 GMC 6500 with 454 gas engine?
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Related Questions

What is wrong with the engine when the engine light on the dash board keeps flashing?

might be a misfire in a cylinder...

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Can no oil in the engine lock your engine?

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