American Dad! - Season 8 Episode 10
Wheels & the Legman and the Case of Grandpa's Key

Stan joins Roger and Steves fictional detective agency, but he ruins the fun by being extremely incompetent at his "job." Roger demands that Steve fire Stan, but Steve cannot bring himself to do it and ends up lying to Roger. Things take a turn for the worse when Stan is kidnapped, and Steve must tell Roger the truth.