Shortly after I bought the car last year the check engine light came on. Service guys put a code reader on and said it was probably caused by aftermarket exhaust. It was out for a while after reset, then came on again a few weeks later. Knowing what it was I ignored it. After a couple months it went out on its own. Car is a daily driver - I commute about 30 miles a day. The bulb is fine (it lights during startup), car seems to be running fine. Any ideas? Thanks