hey guys i posted this over on the 2010 forum but some of you have the same enigine so ill ask you too.

i have a 2010 xl with the 4.6 2v, and anytime i put the a/c or the heat or just air on the idle is rough as heck, and when i turn off the air it idles fine. is this normal? i replaced the air filter the other day with a napa gold filter, could that be the problem?

thanks guys