I have a 2005 F150 5.4 that started giving me issues last year traveling on interstate. It acted as if a cylinder had failed. Was fine at a certain speed but when I pressed on gas it constantly stuttered. Stopped by Avanced Auto and they read the code (don't remember what it was but there were 2). Put some engine treatment in and it started up fine. It appears that after you shut off it clears the check engine. Did some research and decided to clean the throttle body and MAF sensor. All was fine until few months ago it started do it again. It does it mainly going up a hill while in O/D. Once I give it enough gas to downshift it doesn't do it. It seems to stutter until it down shifts. Any ideas? It's not throwing a CEL but it bugs the **** out of me. Could it be the throttle body sensor? All responses appreciated. Thx

Brian

 

How many miles on the truck, how many miles on the spark plugs? That sounds like a low grade misfire.

 

Sounds like plugs. Also, how many miles on the fuel filter?

 

Has 78K miles on it. Fuel filter has approx 40K miles on it. Could it be the Fuel Delivery module under the spare tire? I have seen some posts where people replace this but don't know if it's because of the issue I am having..I also only run Shell gasoline in my vehicle so don't know if that matters.

 

It could be the FPDM, but at 78k it's time for spark plugs. Fuel filter should be changed every 30k.

The CAI could be causing a lean condition - you really should get a programmer and custom tunes - or put the stock airbox back on and do a Gotts mod to it.

 

I do have the EDGE tuner. Been on there for about 6 years..

 

If you are using an EDGE with canned tunes you *ARE* running lean, and slowly but surely cooking your engine. I bet when you pull the plugs they will look burnt.

 

The Edge canned tunes are for stock intakes

 

Yes, and they work fine with the Gotts mod because the MAF is in the stock position. Relocating the MAF, which aftermarket intakes do, changes the metering strategy.

 

Well MF'r. I had no idea that the edge tunes were meant for a stock intake. Don't think that was ever said when the the rage for the edge tuner started back in 05/06 for the f150's. Also, thought tune up wasn't needed until 100K. If I need to do it then so be it. Guess I need to put the stock intake back on. Don't even know if I know how to do it since it has been 8 years since I took it off. At least I still have the darn thing. I would prefer not to get a custom tune ($400) but rather do the GOTTS instead ($20). How much a difference are people seeing with the GOTTS method.

Thanks GLC and others for steering me back on track. Haven't been following all the mods for some time so obviously didn't know that edge w/ aftermarket intake was causing to run lean and frying plugs..

Also, I was only running the transmission tune on the EDGE so don't know if that makes a difference or not but sounds like it's not that I had the edge but that I was allowing more air in than needed.

 

I have a 2005 F150 Lariat and I have the same problem! It only does this when I hit past 40 mph and put my foot on the gas to stay constant. If I put lots of pressure to where it shifts, it doesn't stutter. Let me know if you find out what it is!

 

Do you have a tuner? If so, is it custom tuned? If not, do you still have the factory intake? I hate to spend several hundred dollars getting plugs replaced only for problem to still exist.