Got a 2009 Honda Accord that's been idling a little rough and shuddering/vibrating. When I turn the steering wheel, RPMs quickly jump from 500 - 1100 and then quick drop down and car sputters like it will stall then returns to normal.
Only happens when stationary or when I come to a stop at a light. Had alternator checked and they told me it barely passed and has 12.5 - 13V output. I also noticed it takes 3 seconds from turning the key to the engine starting. Battery is new and was putting out 12V. Any test I can do to isolate? I don't want to just throw parts at it.