WhippleCharged '15 5.0 ... code & shudder

Old 06-13-2019, 05:22 PM
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WhippleCharged '15 5.0 ... code & shudder

Looking for some insight. I am getting a "Randon Multiple Cylinder Misfire" code (PO300) when I drop the hammer on my truck. I only get it at full (or almost full) throttle. Fuel mileage dropped waaaay off... power is not optimal ... I'm thinking plugs or coils .. I contacted whipple .. they want to update tune/reflash .. I really liked my last tune from them (been getting avg of 19mpg) .. until recently when this started ... I have 71,000 miles on it now.. had both cats replaced a couple months ago... I run 93+ octane only ... Boost gauge still shows 13PSI as it has since I put the smaller pulley on it. I ordered new NGK's to replace plugs .. next may be coils .. after that... me and whipple tech support may get to know each other.... My RWHP dyno'd at 647... I know right now i'm not there...
Old 06-13-2019, 05:30 PM
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Does Whipple have a specific plug and gap recommendation? This is pretty critical with supercharged engines. Stock Motorcraft or Denso coils should be as good as anything else.
Old 06-13-2019, 06:05 PM
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You might need need different heat plugs. Possibly colder plugs.

Here's some good advice:


Although, Whipple should be armed with this information, especially since you are giving them the code and what you've got.

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