A preliminary exam is set for Sept. 15 for the Pontiac man charged in a year-old drive-by shooting that killed a Pontiac teen and wounded three others.During a probable cause conference in 50th District Court on Tuesday, Ashton Kevin Greenhouse waived his right to have a preliminary exam within 14 days of his arraignment as requested by his attorney, Dov Lustig, who said he needs more time "to review copious amounts of discovery.