Ford Repair: service engine light, speculation

Question
i have a 2000 f150, and driving down the road the check light started flashing, not staying on. Just flashing. when i start to apply gas it runs reall ruff. especially on take off. it feels as if the whole motor is knockin, or rockin. what could this be?

Answer
Let's try to stay away from speculation as best we can.Do this for me.Take the truck to you're nearest parts store A.S.A.P.They will be able to check you're trouble codes even with the light off for free.Then,let me know what the trouble codes are and I can help you from there.