According to the Indiana Radio Archive and Wikipedia (pages linked below)…
Z-102.3 debuted in January 1999, making this a very early aircheck in that station’s history. The call letters changed from WGL-FM to WCKZ in either March or April of that year.
In March 2001, the station (and WCKZ calls) moved to 94.1 FM, and the format changed to Urban AC (supposedly with the new name “Z-94”).
At the same time, 102.3 became the new home of WEJE (formerly on 96.3), with a Modern Rock format (possibly calling itself Extreme 102.3)…later becoming X-102.3 with the WXTW calls.