Ok my dad has a 2005 auto with no power while pulling. He has had a cp3 replaced and the ecu. Still has the same problem. Injectors have all been checked fuel pump has been pres. and flow tested and the fuel has been tested for water. When pulling it will start out say 40mph at the bottom of the hill and will be on the floor at 5 at the top we had to stop and low lock it to make it up one hill. We are in northern missouri the hills are steep but we have never had this problem before. While unloaded it has a little surge at 70. I am out of options. Help