I had my 60K tuneup and the dealer put in new platinum plugs. Immediately after leaving the service department, I was sitting at a traffic light with my foot on the brake when I felt a slight bump. I noticed that it recurred every 15 to 30 seconds and that the tachometer would take a little dip each time I felt the small movement in the car. At higher speeds I can feel the engine "miss" when I accelerate. I recently pulled a pop-sup for 1000 miles and the situation was awful. The dealer told me that they could not replicate this and therefore, they couldn't help me. The service manage said that the on-board computer would register each time an engine misfired, and since he could find not error messages, there was nothing he could do.
I suspect that there is some kind of wiring issue where the mechanic either failed to properly reconnect all of the wiring (which is extensive) or that there is a short or an open in one of the wires. Can anyone help me on this issue? Thanks.