A 6'2" quarterback, Klingler rewrote numerous college passing records for the Houston Cougars from 1988-1991. On November 17, 1990, Klingler threw 11 touchdown passes against Eastern Washington University at the Astrodome, and on December 2 set the NCAA(division I) record for most yards gained in a single game, 716 (since surpassed by Connor Halliday in 2014). In his four seasons at Houston, he completed 726 of 1,262 passes for 9,430 yards and 91 touchdowns, all of which were school records at the time. Klingler set the NCAA record for touchdown passes in a season with 54 in 1990. His single season touchdown pass record stood for 16 years until it was broken in the 2006 Hawaii Bowl by University of Hawaii quarterback Colt Brennan with 58, though Brennan needed three more games than Klingler to break the record. Klingler made a valiant push to win the Heisman Trophy but was eventually beaten by Ty Detmer of Brigham Young University and Raghib Ismail (runner-up) of Notre Dame. Klingler remained a stand-out for the University of Houston and still ranks in the top ten for career touchdown passes and yards in a career.
Klingler injured his elbow and shoulder in the offseason before his third season. After the 1994 season (his third), he underwent elbow surgery. Being informed that his injury was career ending, he knew that his career was all but done. Before the operation he could heave a ball 85 yards; afterward he struggled to reach 35.
After the NFL
Klingler entered school at Dallas Theological Seminary, earning both a master's degree in Theology and a Ph.D. in Old Testament studies. In June 2010, he became the director of DTS's Houston extension. On April 15, 2012, it was announced that Klingler was elected as assistant professor of biblical studies at Southwestern Baptist Theological Seminary’s Havard School of Theological Studies in Houston. Klingler was also an analyst for the University of Houston's football radio network from 2006 to 2008.