In the mid-1970s, President Steyn played a minor role in the Angolan Civil War as a part of South African operations against the communists.

A pair of American 12.75-inch (324 mm) Mk 32 triple-barrelled anti-submarine torpedo tubes were added amidships and their electronics were upgraded, including the addition of a Thomson-CSF Jupiter early-warning radar atop a new mainmast and a Selenia Orion fire-control system.

The flotilla departed three days later, bound for home, but they were forced to put into Freemantle when a pump in President Pretorius burnt out en route.

[1]: 227 Several months later, the ship departed Simon's Town on 1 September to escort the newly completed, French-built submarine SAS Emily Hobhouse to South Africa.

[3]: 128–31  While visiting Luanda, Portuguese Angola, the ship's helicopter needed to make a test flight after replacing the main rotorhead and was lost with all hands on 25 November.

President Steyn and Emily Hobhouse arrived on 10 December and the frigate made another voyage to Toulon the following year to escort the submarine Johanna van der Merwe home from France.

In 1973, the ship, together with President Kruger and Johanna van der Merwe, visited Lourenco Marques (now Maputo) in Portuguese Mozambique from 29 March to 7 April.

[1]: 228–30 President Steyn played a minor role in Operation Savannah, the South African covert intervention in the Angolan Civil War, most notably when she rescued 26 advisors to the National Liberation Front of Angola who had been cut off after a failed attack on Luanda on 28 November.

However, the accidental sinking of her sister President Kruger in February 1982 gave the ship a reprieve as she was placed in reserve in case the navy decided to restore her to operational service.

President Steyn was towed from Simon's Town on 29 April 1991 and sunk by a combination of missile hits and gunfire from the five Minister-class fast attack craft involved in the exercise.