I have a 04 Lariat 5.4 4x4. I have been having problems with it for over two months now. It bogs bad and has no low end power. I have changed the fuel filter, spark plugs, COPs, cleand the MAF and throttle body, had the cam phasers replaced, and today had my cats replaced and still no fix. Please help with any advice. Im thinking the fuel injectors but after all this im not sure about anything. Thanks for any suggestions.

 

bump

 

You'll have to give much more info if you want help from the great group of guys/gals on this forum. Did the "check engine" light come on? Are you "throwing any codes"? Did you disconnect and reconnect the battery at any point after making all those changes you've mentioned? Is it bogging down off the line, at wide-open-throttle, or all the time? Did you check any plug wells for compression leaks? I didn't think that the 04s had problems with their fuel injectors, but you're running out of options.

Give more info and let's see what we come up with. Good luck!

 

Sorry, I was just in a hurry and frustrated. If I try to accelerate quickly from a stop or floor it it will barely move. When I get to hills or try to pull a trailor it bogs down too. if I ease on it and cruising on flat ground its fine.

I'm very frustrated with it and its made me doubt my pretty big loyalty to ford. I love the truck and don't want to sell it but I can't throw thousands of dollars in it either.

 

Instead of spending money throwing parts at it, have you considered taking it to a good Ford dealer for a diagnosis?

Are there any mods, or is this a 100% stock truck?

 

Is the acceleration issue only at low rpm? What happens at higher rpm? Have you pulled codes?

 

Checked fuel pressure?

 

If you hold it too the floor it doesnt clear up until it gets to high rpms and not completely even then. I have taken it to two ford dealers. First took two weeks to tell me they thought it was the cam phasers. I then took it to a second that agreed so i had them replace them. That didnt fix it so they said cats. I had them replaced with magnaflow high flows and still no fix. Its hasnt thrown any codes or CEL over this entire time. Im reluctant to take it back to the dealer now though because it doesnt seem they really know and im sure they are fine with just guessing as long as they are getting paid.

Also, I have a AF1 cold air intake and troyer custom tuning. It doesnt make any difference though with the tunes in or stock. I have had this setup for about 40,000 miles now so i dont think its related.

 

How many miles have you put on it since the problem started?
I was once told Ford dummed the computers down and it takes a little time to
throw some codes.

 

sounds like it could be a vac leak no power @ low rpms it would not be the first time that the fords ECM'S didnt trow codes that were there.

 

have you tried checking for codes even though there is no CEL?

 

One reason I asked about rpm is I've seen a few threads with similar symptoms and it was related to the torque converter. Some had to do with a TSB and a reflash and others were an electronic solenoid in the transmission. You might want to do a search here and in the transmission forum and see if the symptoms are the same.

 

From what i described does it sound like a fuel injector issue or the transmission porblem described. There is also a ticking noise from the passanger side of the motor, almost like an exhaust leak. I have checked as well as the dealer and there havent been any codes. The truck has been like this for going on 3 months now so it should have thrown the codes by now if it was.

 

It would be throwing codes with an injector issue. I'm not sure if the TC solenoid would throw a code.

 

How difficult/costly would it be to replace the solenoid?