Hyundai Repair: 2005 hyundai elantra hissing noise, 2005 hyundai elantra, hyundai elantra

Question
I have a 2005 hyundai elantra.  A couple of days ago I had it out on the highway and it was about -20 degrees celcius.  After 30 minutes of driving it started to make a hissing noise.  When I went to slow down it smelt like oil and the check engine light went on.  I stopped the car and checked everything out but couldn't see anything wrong.  I turned the car off and when I started it again the check engine light did not come back on.  It hasn't done anything like that since then.  I took it to the dealership and they said they couldn't find anything wrong.  What could have been or was the problem.  

Answer
Unless there was a significant period of time between the check engine lamp coming on and when you took the vehicle to the dealership, there should have been a stored code in the vehicle's computer reflecting the problem the computer saw that caused it to turn on the check engine lamp.  

It's hard to say what the problem would have been.  Ideally, I'd want the diagnostic trouble code to narrow down the possibilities.  The odor suggests that there may have been an electrical device failing or something rubbing excessively, but I'm having trouble thinking of anything fitting that category that would cause a check engine lamp.

If your check engine lamp stays out and the odor doesn't reoccur, chalk it up to being a one time occurrence.  If either comes back, take the car to the dealer and demonstrate the problem.  If your check engine lamp is on, request for them to tell you the trouble code.