I have a 1999 C230K with approx 68K miles. Last Sunday, the battery was dead and the starter wouldn't crank. I jumped the car and it drove fine the rest of the day. The next day, it seemed to be cranking a little slow, so I took it to my indie to check the battery. He replaced the OEM battery with an Interstate and immediately upon leaving the shop, the "check engine" light came on and the car started idling roughly. I took it back to the shop, they checked and thought it was the computer system in the car resetting itself. Indie told me to drive it for a week and see if problem persists. The car drove fine for one day and then started idling rough and check engine light came on again. It seems to only run rough when idling, not at higher speed. Any thoughts?