I research the Irish Family History Foundation's database. It contains 12,000,000 surviving rcds for abt 65% of Irish counties. Rcds are increasingly sparse B4 1840, rare B4 1800.
Note 1 - Without a KNOWN county, the chance of an ancestor's rcds NOT being in this database is AT LEAST 35%.
Note 2 - Only 1/2 of Co. Cork's rcds are in this database.
Note 3 - The RC church kept control over most parish rcds from Tipperary (north). These are ONLY available thru the Tipperary Family History Research center at a substantial fee (regardless of outcome).
For Dan(iel) Fahy B 1824 +/- 4 yrs somewhere in Ireland with the father's forename unknown, I found 1 rcd in 1822, Co. Cork. The father's forename for this rcd is Thomas. This doesn't match your criteria exactly. This makes it doubtful for being your ancestor.
For Marg(aret) Hogan B 1834 ditto with a father forenamed John, I found 6 rcds: 2-1832 Galway, 1835 Tipperary, 1836 Galway, 1837 Galway, and 1838 Cork. Ditto.
The rcds for your ancestors may not have been digitized yet (35% chance). Suggest you wait until the database is more complete - specifically until the rcds for Clare have been transcribed.
Google the Foundation's name to lead you to this database. Register, opt to be notified as rcds are added and browse. Pls post your search results to my genforum msg.