ˌɔn dᵻsˈɛmbɚ sˈɛvən, nˈaɪntiːnhˈʌndɹɪd nˈaɪnti ˈeɪt, ɐ fˈɔːɹmæt swˈɑːp əkˈɜːd bᵻtwˌiːn ˌɛksˌeɪtʃˌɛfˈoʊ ænd zˈɛkɚɹˌɛfˈɛm, wɪð ˌɛksˌeɪtʃˌɛfˈoʊ ɐdˈɑːptɪŋ ðɪ ˈɪŋɡlɪʃ klˈæsɪk hˈɪts fˈɔːɹmæt "jˌuːnɪvˈɜːsəl stˈɛɹɪˌoʊ" ðæt hæd bɪɡˈʌn ɪn nˈaɪntiːnhˈʌndɹɪd sˈɛvənti fˈoːɹ, wˈɛɹæz "lˌæ zˈiː" mˈuːvd tə zˈɛkɚ.
On December 7, 1998, a format swap occurred between XHFO and XEQR-FM, with XHFO adopting the English classic hits format "Universal Stereo" that had begun in 1974, whereas "La Z" moved to XEQR.