Went for a ride today and my check engine light came on. It starts, Idels, and runs fine I filled up today but it want till later on when it came on. How do I check what code it is or what do you think it could be? Before it came on I thought I smelled plastic buring but how could I smell that going 70? Point me in the right direction before I'm forced to go to HD and give them my liver to fix it?