I just had these codes run on my 98 F150 4.6 ltr. I did a search and found out a K&N could have caused this and it does seem like it came on after I installed it however I've tried cleaning the little maf wires with a qtip and alchohol and that doesn't seem to matter.

Any ideas? Anything else I should check?

Thanks..

 

After cleaning the MAFS wires, did you follow the procedure to clear the PCM or take 2 driving trips over a sustainted 48 MPH ?

The code does not just go away, you need 2 full drive cycles for the PCM to turn it off, or disconnect the batt, and turn on the head lights for ~ 5 min or so, then re-connect, and start it up again, and take it out for at least 1 drive cycle.

The other thing to keep in mind, is when you say you installed a K&N do you mean FIPK, or K&N drop in element ?

If you knocked any of the lines off the intake installing a drop in filter, or did not get any of them seated correctly installing a FIPK, this will show as un-metered air, and cause a lean code, as more air is making it into the system, then the MAFS is reporting.

Ususally both codes together mean the MAFS is not reading the actual amount of air in the system, which is either from faulty readings ( dirty MAFS wire ) or not reading all the air in the system ( leaks in the intake after the MAFS ). These are the most common, but not the only ones.
If you can check all the connections on the intake, and let us know if you cleaned the PCM, that is a good place to start.

Good luck