05 Camery electrical problem
 

Hi I need some advice, my car will idle around 900 rpm normally. But recently it will drop down to about 500, this is not consistant but happens quite often. It also is loosing time on the clock, for instance i'll come out in the morning and the clock will be a few hours off. These problems started about the same time !! I just recently did plugs and a new air filter, possibly I disturbed something taking the top off the air filter or upset some electrical device. I am a pretty good mechanic and have rechecked my work.
Thanks for any thoughts. Tom