Lord Ganesha is always worshipped before starting any Pooja or Homa. Lord Ganesha removes all obstacles. Ganapathy Homa should be performed on all auspicious occasions should also be done on Shukla Chathurthi day.
If any one is running Ketu dasa or bhukti or there is some dosha of Ketu in the horoscope, one can perform Ganapathy Homa and get-relief. Performing Ganapathy Homa once every year will give prosperity, health, and wealth.