Went to take car out for a ride today and it would not idle, car starts fine . If I hold the gas pedal at the same spot the engine RPM will go down a few hundred RPM and then come back up.When I take my foot off the gas RPMs drop off and car stalls. The only thing I had done was to take off my K&N fiters and clean them, they were off the car a few days to dry.Any ideas on why it won't idle is appreciated