Still three incompletes for OBD II
 

My inspection is coming up soon, and I have had P0400 codes. I reset and by driving carefully I have no code after almost 200 miles of driving, but still have 3 incompletes on the OBD II and will not pass inspection until these complete. Any ideas of what might be wrong with my system?? 1996 C280 with only 60k miles drives like a dream, and looks almost showroom new. Really want to resolve this.