I have a 2008 F250 SD 5.4L with 335,000KM's(200,000+miles).

The engine light came on a few weeks ago and I cannot seem to get rid of it. I have also noticed when I'm accelerating hard at higher speeds/RPM's the engine light flashes?? After when I get to the cruising speed and let off the gas pedal the engine light stops flashing and stays solid. Also when accelerating hard there seems to be a hesitation, almost like the engine is choking itself. Once it gets passed the hesitation point during hard accelerating it seems fine? I have ran about 6 bottles of Seafood through the engine and gas tank. It definitely helped out but still has the hesitation, flashing engine light syndrome...I have changed the following with still no luck; Please Help.

-Spark Plugs
-Coil on Plug
-Fuel Injectors
-Cam Phase sensors

 

These are the codes I get,
P0301 cylinder 1 misfire detected
P0302 cylinder 2 misfire detected
P0303 cylinder 3 misfire detected
P0304 cylinder 4 misfire detected
P0306 cylinder 6 misfire detected

 

I found your problem.

 

The 5.4's don't like shell fish.

 

Now that you have wasted all that money guessing, you may not be able to afford to pay someone who knows how to troubleshoot the problem.

Considering what you have done, you might want to check the fuel pressure, fuel trim, and check for vacuum leaks.

Post what you find and then we can proceed.

Note: If you drive it for very long with the engine light flashing, you will be replacing the catalytic converters too.

 

engine light "ON" means need repair/service

engine light "FLASHING" engine need help "NOW"

you are causing more damage... and catalytic converters are real expensive..
misfires dump un-burnt fuel into the converters and damages them.