Mixture Control, Idle
 

Have a Peake Research tool and got Fault Code 1c (from Table 0F) for an '02 4.4i. The description for this fault is " Mixture Control, idle, Cyl #1-4"

Anyone know what cause might be or what adjustments a DIY'er can do? (or is this a dealer/independant job) Is this something to do with fuel/air mixture? Vehicle seems to idle and run normally.

Thanks in advane for comments.

i have the same exact problem after i installed AFE intake. Could this be an intake leak? The X runs fine though, but is it safe to drive around like from and to work? Any smoke machine that you guys recommend?

In my case, the crankcase vent hoses were the problem and needed to be replaced. These are the hoses that sit on top of the engine and melt away over time.

figured out by my mechanic. It's the air flow sensor, broken. I dunno why but when i installed AFE, it got broke for some reason. I was very careful though.