I have had my SVX for three winters and winter or not if the motor is not warmed up and I take to a hill the check engine light goes on. I was told once that it was because the motor was running inefficiently and the O2 sensor would trigger. I have taken it to Subaru but since the light goes off after a couple of minutes they say they have nothing to check. But three years later mine is still running fine though I wish I had a more meticulous Subaru service location.
That being said my Father's '92 which he has had since new has never come on so?