What's up guys, I have a 2004 FX4 with the 5.4. When I merge on the highway and really accelerate my check engine light flashes for the next few miles and then shuts off. I can't pull any codes from computer. Any ideas where to start? Thanks Guys.

 

Is it just under hard acceleration? Because it can flash on a bad misfire. You can't pull any codes or you checked and it hasn't stored any?

 

It only flashes from a misfire. Take it to a dealer and they can look at the misfire rate on each cylinder. Or just do a tune up if it's been a long time.

 

x2

 

Yeah just under hard acceleration. I checked and no stored codes. And it is time for a tune up. Thanks guys.

 

I had this exact same thing happen. Turns out it was bad coil and spark plug. Have ford determine which one.

 

I'm new to fords.....but I have an 05 and I've been told the plugs are a BITC# to change out.....talk to the other guys here with experience there.

 

Im not to sure how to post anything on here but I have and 07 f 150 and it runs rough when at an idle. I hsve a check engine light that comes on and then blinks when I try to give it gas. And when I let go it goes back to solid can anyone explain to me what that could be from. Thanks.

 

Blinking means a misfire is detected, steady means your 02 sensors are reading an improper fuel mix, which is probably due to a halfway working coil and/or spark plug.

 

I had the same thing happen I was lucky knew a guy with a obd2 ran it as hard as I could up and down a street by his shop pulled a multiple miss fire code. Changed the plugs cops fuel filter air filter cleaned the throttle body. A few weeks later my cat converter took a crap ford replaced it no charge since it was still under the emissions warranty. Do that and you won't have this problem any more. Also change the fuel pump drive module. Just as a pm thing chances are its going to rust out and die. Read a lot before you do the plug change chances are there o.e plugs. Buy the lisle tool before amazon has the best deal on it and put anti seize on the electrode part of the plug.