GuruJi Pawan Sinha: Know what is Pitra Dosh and its effects

GuruJi Pawan Sinha tells the reaosns of pitra dosh. He also tells it different kinds and astrological ways to avoid it. 
All things obstruct the progress of life. Some defects are known, and some are unknown. One of these unknown defects is Pitra Dosha. Generally, Rahu is behind this. We connect different situations of Rahu with past birth and fathers.