01 Audi Quatro 6 cyl. 180,000 miles runs perfectly. Trouble codes point to coil bank 3, or bank 2, or all three. Clear codes and they pop back up within 10 miles of driving, sometimes sooner. Replaced coil, no change. New plug wires. I don't think this model has a coil module, could be wrong. Any ideas aside the black tape over the check engine light solution?