Today my car is very rough while driving. When accelerating, the engine sounds very choppy, my whole inside of my car vibrates. Once I am going fast, I don't notice it. Also, the service engine light flashes while driving, when stopped, the flashing stops but the light remains lit. Any idea what it could be? I filled up my tank yesterday with premium unleaded, and it was fine driving home. But this morning when I left for work, I noticed the problem.
The light flashing indicates a misfire. It will happen mostly under a load. What to do is have the computer scanned to identify which cylinder is causing the problem. Most parts stores will scan it for free. Let me know what you find. Also, let me know when the last tune up was.