Okay I'm reading up on some of the stuff on the forum and there is a lot of knowledgeable people on here. I have also read some of the threads found some with the same issue but every issue is different.
I am having problems with my truck and I will be working g on it myself. The only thing is I need ideas on what to switch out, replace, etc.
I have a 2006 lariat f150 I drive down the road like cruising and not forcing the acceleration and she drives fine. I go to get on the highway and the truck starts jerking as I floor it. I press the over drive off and it stops. I accelerate to 70 Mph and then turn on over drive and set cruise control and I'm good until I start going up a hill. Or I want to accelerate in over drive.
Today on my way to church I get the cel and I check it and it throws p0420 and p0303. This happen in overdrive but I wasn't accelerating too hard.
From what I read p0420 means bad cats and to replace them
and p0303 could be spark plugs, coils or the spark plug cords.

I am good with oIL changes. And every time I go they check tranny fluid. It just passed smog.
I don't know if it will help but I will be changing the tranny fluid and the filter and gas filter. Maybe even change out spark plugs if time permits it.
Anyone have any other ideas or can set me straight on what I need to do to fix it? And yes I double check the headlight fluid. Lol

 

You need spark plugs, maybe coils, and you need to take care of the issue with the cats.

You don't have spark plug wires, there's a coil on each plug.

 

Hey GLC thanks for the reply. I just took her out for a spin to make sure i really was sure about the description to my problem. I cleared the codes to see if anything popped up again. I got another p0300 code. so yeah it leads me to believe that its not really the tranny.
So i will be changing my line of work from spark plugs, coils and cat. for the cat i dont have a welder so guess ill have to take that in.

I was also thinking it could be the MAF? i press on the pedal and it seams like it takes forever to finally kick in. i would like a quicker response.

 

Fix the misfire and, maybe, with a good bit of luck, you'll find that your cat isn't ruined after all (from the persistent misfires).

I'd plan on a complete tuneup (plugs, boots/springs, and at least one coil). I'd also clean the MAF sensor. Once all that is done, reset the computer's memory and run it for a while and see how it does.

 

Hey projectSHO89 thanks for the reply,
I went down to the store and bought me one of those fancy Haynes books. Just so i can see tune up schedules and maybe it can give me detailed information on how to go about getting deeper than changing out plugs.

Is there a certain spark plug a f150 needs. i mean a certain brand? i remember on my old 1999 f150 i had changed out my plugs from motocraft to botch and my truck ran like crap. Then i took them back and got me the same ones and it ran smooth as eggs.

You said boots/springs. im not sure what you are referring to. or is that just like another coil?
Got it the boot is what goes over the spark plug then it leads to the coil. Is this correct?

And to clean the MAF i would just remove it and clean it with electric cleaner?

 

5.4 3 valve? Motorcraft SP-515. Be aware of the breakage issue! Have access to a Lisle extraction tool and you need high temperature nickel antiseize for the ground shanks. Tons of threads here on these issues. Recommended plug change interval is now 60k.

Boots and springs attach to the coil. You can change them without changing the whole coil and are a lot cheaper.

Clean the MAF with MAF cleaner.

You said you just "passed smog" - using that terminology tells me you are probably in California (every other place calls it emission testing). Better hope you don't need cats, a set that is legal there is about $2500. You won't pass smog again with cats that aren't CARB-certified.