2011 3.5l ecoboost.

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this truck is running a 87octane sct tune in winter weather it will has some preignition/ popping noise on wot. it doesnt always do it when it does it its only right on the throttle snap and goes away. puffs black smoke when it does it . i currently have it running a milder tune cause i dont want any sort of knock/preignition. what should i adjust on this sct tune to elininate this issuesct file 2011 f150.hpt

[Seishuku]

Sounds like it's just blowing out the spark... Try a step colder plug and tighten up the gap a bit.

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ok thanks alot for reply. ill try that. whats the best plug to throw in? currently have oem plugs with 20,000 miles on them

[Seishuku]

Not sure about best plug, as long as they aren't Autolite. lol
I've always been a fan of NGK, LTR71X-II.

Since you only have 30k on the factory plugs, I would just try closing up the gap to .028" or .026" and see if things improve... If not, then maybe look into other changes.