just wanted to pass on a possible cause for these codes. this is on a 01 lightning but should be applicable to others. truck would run fine @ cruise and wot but would sometimes stumble at idle and stall. problem turned out to be pcv vacuum hose assembly that runs to back of lower intake manifold. it has a rubber elbow that deteriorates from oil where it connects to lower manifold and allows unmetered air to enter intake. it is a pain in the a** to get to and sometimes the hiss it makes is masked by all of the other noises in the engine bay. if you get this condition and all other connections are ok then ck the tube.

 

Good one, I'll check it out!

 

it happened to my 01. I got the same two codes and it was exactly what you just said. I stuck my hand behind the blower on the lower intake and the hose was all mushy. I changed the hoses out for a new set from ford and my check light was gone!

they should make this a damn sticky!

 

Thanks for the information!! It seems that a lot of people are suddenly having the lean codes popping up.

I am currently having P0171 and P0174 code problems when my truck idles or when I drive very slow. I will check out this hose assembly. I also purchased contact cleaner (before anyone calls me an idiot--not the type that goes in your eyes) to clean my MAF--it is my understanding that the MAF element can get dirty and not properly read the correct airflow resulting in more oxygen entering the engine than the computer thinks is entering.


Greg