So I haven't driven my car in a while, I've been riding my bike instead. When I was driving it consistently I was noticing that as it heated up it would start to shift hard, had it looked at the, of course the tranny had an 1811 code for EPC. So I drove the car for an extended period tonight, after it warmed up it wasn't kicking hard it started shuddering as it shifted between 2-3, 3-4 but not 1-2. No hard kicking, just shuddering....What gives?