2002 Ford Taurus - Mileage + Distance = problems?

Ok, I know this is really random. But my Taurus has about 170,000 miles on it. And I've never driven it long distance. The engine light is on, but it's been on for months. I think it's a gliche in the computer. I just got all new breaks, and all my oils and liquids changed about a month ago. I want to go on a long distance trip across the state (The Mountains of NC. 300 miles) But I am worried about wether my car will make it or not. What do yall think? The weather is 30 degress compared to the 50-60 degree wether we have in the east. Will this affect my car? What should I do?