Flaherty & Crumrine Preferred Income Opportunity Fund (PFO) N-CSR Certified annual shareholder report (management investment company)

Flaherty & Crumrine Preferred and Income Opportunity Fund Incorporated N-CSR

Exhibit 99.906CERT

Certification Pursuant to Rule 30a-2(b) under the 1940 Act and
Section 906 of the Sarbanes-Oxley Act

I, R. Eric Chadwick, Chief Executive Officer and President of Flaherty & Crumrine Preferred and Income Opportunity Fund Incorporated (the “Registrant”), certify that:

1. The Form N-CSR of the Registrant (the “Report”) fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Registrant.

Date:	January 19, 2024	/s/ R. Eric Chadwick
		R. Eric Chadwick, Chief Executive Officer and President
		(principal executive officer)

I, Bradford S. Stone, Chief Financial Officer, Treasurer and Vice President of Flaherty & Crumrine Preferred and Income Opportunity Fund Incorporated (the “Registrant”), certify that:

1. The Form N-CSR of the Registrant (the “Report”) fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Registrant.

Date:	January 19, 2024	/s/ Bradford S. Stone
		Bradford S. Stone, Chief Financial Officer, Treasurer and Vice President
		(principal financial officer)