My ford 2004 f 150 heritage just started to have a rough idle on the way to work. It only does this when you are stopped. It even shut off once at a red light tonight. I and not get any codes off of it. I had this check and it would not even connect to the turck to get the codes off. Not sure what to look for. It has 111000 on it and have never had a problem with it. Any help would be great!

 

Possible miss fire in one of your cylinders or not firing at all in one. You said not get any codes, you mean you can read the trouble codes and comes up no problems or just no engine light coming on?

 

If the code reader won't connect, replace the cigarette lighter fuse. The code reader must be CAN-capable.

With 111k, it's due for spark plugs. Which engine do you have?

 

Thanks for the help got the fuse replaced and found out that there are 2 bad o2 sensors. They told me they were on the under side. Has anyone done this replace on a 2004 ford?

 

What are the exact codes, please? If they are P0171 and P0174, you do *NOT* need new O2 sensors!

Again, WHAT ENGINE please?

 

Those are the codes and it is 4.5 v8 exten cab with 8' bed 2 whell drive. So what now?

 

The most common reason for both banks lean is a major vacuum leak - and the most common failure is the PCV elbow behind the intake manifold. It rots and cracks.

 

I have checked all the air intakes and they seem to be good and tight. Have any other ideas be fore I wimp out and take it to the shop?

 

Have you followed the PCV hose back from the PCV valve to the elbow behind the intake manifold? You can't SEE it, you have to do it by feel, and you need small hands.

 

yes I have check that and it is good

 

GLC was right, after messing around I checked the PCV hose back from the PCV valve to the elbow behind the intake manifold. I ened up finding a crack on the elbow, it was on the inside part of the elbow. SO leason learned, pay attention to the master and double check everything! Thanks GLC.