I keep having a misfire code...same one every time p0301...truck runs ruff between 55-65mph...real rough...above that or below it, is perfect.

my engine light will start flashing, its kind of scary, makes me want to get off of the hi way immediately. Is this just the spark plug? or coil? or ?

i live in las vegas...it is always hot. truck doesn't blow smoke..other than this..it runs great.

5.4l v8 SOHC

advice will be greatly appreciated.