alright, so I've been getting this code on and off for the past couple months but today when it went off I immediately noticed that the car has a slightly lumpy idle and the shifter is slightly shaking. Usually only get it during a cold start but today am getting it even after the car is warmed up. I've changed spark plugs just a few thousand miles ago. It is only the d4 code from table 1b of the peak codes and nothing more. The other thought occurred to me that it is the coil pack. The car only does the odd lumpy/shakey feeling when at idle not under load, the car starts and goes fine even if I give her some throttle. Anyone have any other thoughts? Need to get this resolved before friday as I'm getting married saturday and need the car running properly before then. Thank you!