In the 1990s, Wahls was among the strongest of German chess players. He represented Germany in the 1990 and 1992 Chess Olympiads, and in 1996 and 1997 German championships. In 1998, Wahls qualified for the FIDE World Chess Championship, which was held a year later in Las Vegas. There, he defeated Altin Cela of Albania in the first round by 1½ – ½, but fell in the second round by 0 – 2 to Ukrainian Vassily Ivanchuk.