Changing to a different format reassigns the texture coordinates. The DXF you import and export as an OBJ will have different texture coords than the original OBJ. Besides, DXF doesn't support UV mapping, if I recall, I could be wrong. If you still have P3 loaded, export your P4 figure as an OBJ, then import it into P3, then out again as a whole. Have you tried just loading the original P4 model straight out of the Geometries folder, or is this concerning a CR2 that didn't include the original mesh?