Powerv08

Hi there am new on the form

I owne a 2005 mustang Gt V8 4.6 3 valve enging

5 speed manual tran the car was run very strong till 2 month back
Out of no where it was start been lossing power at idel like is fine the only issue is if i drive hard at speed 100 mile approxmetly will be miss firining and with no erorr code i have check the spark plug and found ots been burnout so i have replce it all the 8 plugs after that i notes that the car on hi rpm was no miss fire but i notes a big loss on power so i have check the fuel reading and found its been at idel will be at 39 psi
And at hi rpm is same at 39 psi and just to be in the safe side i have replce the fuel filter to avioed any restraction and again after 10k mile i have miss firining issue i check the spark plug and its been gon bad like lean condition so now i have no idia from where to start checking plz help

Powerv08

QUOTE=Powerv08;8468959]Hi there am new on the form

I owne a 2005 mustang Gt V8 4.6 3 valve enging

5 speed manual tran the car was run very strong till 2 month back
Out of no where it was start been lossing power. It was at idel is fine the only issue is if i drive hard at speed 100 mile 3rd gear approxmetly will be miss firining
with no erorr code i have check the spark plug and found out its been burnout so i have replce all the 8 plugs after that i notes that the car on hi rpm was not miss firing but i notes a big loss on power so i have check the fuel reading and found its been at idel will be at 39 psi
And at hi rpm is same at 39 psi and just to be in the safe side i have replce the fuel filter to avioed any restraction and again after 10k mile i have miss firining issue i check the spark plug and its been go bad like lean condition so now i have no idia from where to start checking plz help[/QUOTE]

SpartaPerformance

No DTC at all?