The Bald and the Beautiful - S3-E7
Other mistake: At the end of this episode, there is a typo in the credits: "Directed by" is written twice. (00:22:30)
Other mistake: Al, Peg, and the kids go to the beach. Steve and Marcy are sitting not too far away from them, yet they never interact with each other. They had to see each other they just act like they don't notice each other.
The Bald and the Beautiful - S3-E7
Other mistake: Al and Steve are using Dr fur for growing hair. After using it, Steve says it was recalled. Later in the show, Peg says she is going to the store to buy Dr Fur because it was the only thing that Buck would eat. If it was recalled it wouldn't be available to buy anymore in the store.
Answer: It was one of the hoses connected to the engine, nothing specific, but to indicate that Al tampered with the vehicle.