error code A6

After a small rear end accident (i was hit) the check exhaust light came on. Shop says the error codes are po1198 and po1199 and that the po1199 means the ground fault has failed on the computer. Does this sound like something that would be caused by a small bump? TIA

Is the car running the same? I've had an exhaust sensor gone for quite a while on my 96 A6, my mechanic cautioned against replacing it as the other 4 sensors have a tendency to go if you do, and they will screw up the way the car runs and need replacing.