OK guys, ' Check Engine' light is now staying on anywhere between five seconds and two minutes at a time. Still no rhyme or reason that I can see as to why it should be coming on, it's just intermittent. Some days it doesn't come on at all and others it's on and off all day. Today though has been the worst coming on for protracted periods when both moving along and sitting in traffic. I've checked all fluid levels and listened for any strange noises, but nothing seems out of order. Should I be going into panic mode right about now?