Enhanced wavelength tuning performance up to 38 nm of an integrated interferometric injection laser in a Y-laser configuration is reported. To the authors' knowledge, this is the highest tuning range achieved up to now by electrical tuning of an integrated laser structure. In the laser wavelength span between 1532 and 1570 nm the sidemode suppression is generally better than 20 dB and can be as high as 30 dB.