I just installed an intake on my 03 6.0L HD, and now its having ideling issues. Idles way too low 3 to 500 rpm's and stalls often. Ive double checked all of my clamps to make sure that it isnt sucking outside air past the MAF. When I unplug the MAF harness it really starts to idle rough, plug int back in and its fine for a while then eventually does it again.

I accidentally dropped the MAF sensor during the isntallation, could that have possibly damaged it and be the culprit of my problem?

re-install stock intake with MAF and see if that cures the problem

I've run K&N on everything I've ever owned and never had any problems, including a cold air kit on my Duramax, not to mention selling them and installing them through my shop. I'd look at a dropped MAF sensor as a more likely culprit than the K&N.

the maf might have gotten some oil from the filter being over oild while shipped. clean the maf with some cleaner reinstall it with the stock filter and see if it changes. If not could be the maf. Are you getting any codes from it?

I'd bet you just phugged up the sensor when it fell. Sometimes if you overoil the K&N's they could also gum up the MAF.

I already pulled the MAF to check for oil, it was clean, I cleaned it anyway, still does the same thing, Im gonna switch back over to the stock air box and see if it still acts up.

The MAF is somewhat sensitive. Try tapping on it while it's acting up and see if that changes anything.

If you dropped it from more than about a foot or so, chances are it's' f'ed.

When cleaning one, make sure you only use a cleaner labelled for use on a MAF.

I'm guessing its F'ed, switched back to the stock setup and its still acting up...new maf is on the way.

I don't know where you're getting your replacement but I'd go with OEM or NAPA. I've tried several from Auto Zone and Advance and went through several before getting a good one.

tighten the gas cap, take it off then re tighten it and see if that changes it. Sometimes changing the filter will shoot a lean condition to the comp, many times its the cap, wont allow pressure to build.