Epitaxial YBa2Cu3O7 layers with 45 degrees in-plane orientation have been grown by Injection CVD on MgO substrates polished off-axis to within 1.4-1.9 degrees of the [100] direction. This new single-source CVD process is based on computer-controlled injection of precise microdoses of a metal-organic precursor solution into a CVD reactor. A wide range of solution compositions was tested to investigate compositional effects on phase purity, surface morphology, texturing and superconducting properties of the prepared films. The highest quality films with pure 45 degrees texture had a smooth surface, zero resistance T-c (R = 0) of 88-89 K, and critical current density J(c) (77 K) above 10(6) A/cm(2).