It is unfortunate that there are scheisters out there that have no regard for the customer or for doing things right the first time. You may have to resort to a small claims court suit, or a letter to the BBB. The fact that the same code reappeared after servicing indicates a poor job was done. The system can actually be requested to check the purge system by a good scanner. A good tech is priceless in such matters. I will help where I can here. Ray