I have a 2006 F150 5.4 V8 with 221k on it. It recently started to run real rough at low idle when slowing down. It also dies at low idle. This does not happen all the time. Any ideas?????

 

I am a bit shocked it took that long to do that... Mine did that a few months ago at 86K miles...

Assuming you aren't throwing any codes...

Clean your MAF and your throttle body (take the throttle body OFF the manifold before you clean it!).

Also make sure your air filter is clean...

 

Ever change the plugs? Done all routine maintenance all around? Check the cats for clogging?

 

When did you change the fuel filter last?

 

I have never changed the fuel filter and it has been about 100k since last plugs. Dealers in my area won't quote a firm price for the plugs. Last time I was charged $900 to have them changed. Can't afford that right now....fairly handy is it something I can do? They way everyone talks about it it sounds like a nightmare.

 

That could be your problem. I always use motorcraft filters, some others use fram and wix but fram would be my LAST resort. Not that bad to do. There are plenty of threads about it. Just don't force anything or you'll bust the plastic clips off. Need to get the disconnect tool. They are just a few dollars at parts store.
Read up on the threads here on fuel filter replacement and you'll have no problem. I change mine about every 20K miles.

 

What I see out of most fuel filters after 20k miles....

 

Fuel filters need to be changed every 30k and plugs in a 3 valve every 60k. You need both.

If the last set of plugs was properly installed, they should come out okay. Start running Techron in the gas to help burn off the carbon.

As said, with that many miles on it the TB and MAF need cleaning.

 

Thanks all for the info. I ran the codes today and came up with a ton of codes. Most seem to be related to the O2 sensor Heater Bank 1 & 2, and a couple stating Camshaft Position Circut Malfunction, Camshaft Position Sensor "A" Circut. The Cats are cut out on mine but hte O2's are still there. Do I just need to replace them?

 

Having the "exact" codes that were thrown will help answer that. Or you can look here: http://engine-codes.com/

 

Codes are as follows: P0345, P0340, P0430,P0059, P0135, P0155, P2195, P2196, P2197, P2198

 

Test the battery first. But considering you are getting stuck lean AND rich codes, you may just want to replace the O2 sensors. I'm by no means an expert on this. That's where I'd start.

Have you tried clearing the codes and seeing which ones come back first?

 

All those codes are symptomatic of a blown fuse. I don't remember exactly which one it is but I think it's PCM-related.

 

Looking for some ideas to diagnose my 5.4L 06 F150 with 60k miles. It was running a little rough every now and then so I replaced the fuel filter, air filter and cleaned the MAF. I unhooked the battery to replace fuel filter and it reset the computer im assuming. After I swapped out filters and cleaned MAF it ran 100 times worse. It wouldnt idle and dies constantly at lights. The fuel filter is installed correctly. I was thinking that reseting the computer reset the system. Any suggestions of what to check?
thanks

 

When it runs rough at idle can you do a quick stab on the gas and clear it up? Then sometimes when it drops back down it's smooth, other times it's rough again? I don't wish this on anyone, but you might want to start reading about the camphasers.