From the Coke and Pepsi websites a 12oz can of Pepsi has 41g of sugars while a 12oz can of Coke has 39g of sugars, so the Pepsi is, objectively, sweeter.
Interestingly Pepsi includes both HFCS and sugar, so what the OP describes as "too sweet" might actually be a flavor palate that lacks that bit of sugar in addition to HFCS. (The exact mix is not clear, though Pepsi contains more "CARAMEL COLOR" than sugar so it seems suspiciously like the Pepsi is nutritionally the same as Coke with an extra 2g of sugar in addition to 39g of HFCS.)
Interestingly Pepsi includes both HFCS and sugar, so what the OP describes as "too sweet" might actually be a flavor palate that lacks that bit of sugar in addition to HFCS. (The exact mix is not clear, though Pepsi contains more "CARAMEL COLOR" than sugar so it seems suspiciously like the Pepsi is nutritionally the same as Coke with an extra 2g of sugar in addition to 39g of HFCS.)