I just got my CSVT scanned and the codes that came back were PO172 and PO175 both banks are running rich. Does that mean that I have two o2 sensors that are bad or could it be something else? If there are multiple o2 sensors that are bad, how do I tell which ones are bad?

Thanks guys, I am new to CSVT's so this is a learning experience.

2001 Volvo S40-Perrin MBC@ 11psi, EST intake, 35% tint, still slow