2013 SHO Misfires under heavy load

[topazoboom]

Hello everyone,  hoping someone can help as this has me stumped.

Under heavy load I get misfires on cylinder 2,3,4,5,6, but driving around with half throttle I have full power and runs smooth.
The car idles fine, some stuttering when the car is cold, but its done that since I bought it in 2013.

Has anyone experienced this or something similar?

Thanks in advance

 

[SHOdded]

Sorry to hear!  How many miles on your SHO?  When were plugs last done?  Do you get any fuel smell?  Cleaned the MAP. And IAT sensors?  Checked intercooler for buildup?

 

[topazoboom]

I am doing plugs tomorrow, 106k km on it, I will check the sensors too, Thanks

 

[SHOdded]

Post pics of the old plugs please   SP534's for the new ones, or ...?

 

[ZSHO]

Welcome aboard the E.B.P.F!  Is this for your 13-SHO!
Agreed with SHOdded ^^^ and check the plugs &  (COP).
It makes you wonder if the original Motorcraft platinum plugs are still installed.  Z

 

[topazoboom]

Changed the plugs, checked the MAP and IAT sensors, looks like it was the plugs, full power under full throttle again.  Tha kas for the assistance guys.  Hopefully the attached picture comes through.

 

[ZSHO]

It looks like the plugs needed to be changed IMO! hopefully its a permanent viable fix....BTW Fixed the above PIC for ya & Best of luck.  Z 

 

[SHOdded]

X2, hoping this is THE fix.

 

[TopherSho]

Changed the plugs, checked the MAP and IAT sensors, looks like it was the plugs, full power under full throttle again.  Tha kas for the assistance guys.  Hopefully the attached picture comes through.

that looks familiar.. i had that happen in about 12k miles when i ran 1 stage colder plugs.