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: Peg reads from a headline saying "[Marcy] announces NBC fall schedule, people still disappointed." But the text below it reads "State officials..." showing the text doesn't belong with that headline. Also when you see each headline the article is the same for each one.
Other mistake: When at the gas station, they are out of gas. He doesn't put any gas in but later Peggy starts the car up and drives away.
Other mistake: Al's and Peggy's birthdates are around 1948/1950, respectively. Supposedly, Al married Peggy after she got pregnant the day of his 4 touchdowns in high school in 1966. How could Kelly have been born in 1971?
Other mistake: When Steve wants his money back, Al asks how much was Steve bragging about earlier ($5) he could take and make a fortune, instead of giving Steve $5 it's a $20 bill.
Other mistake: When the fat woman gives them the straws, there is no reason why one would already be cut short. They didn't cut the straw. How did they get a short straw?
Dead Men Don't Do Aerobics - S4-E2
Other mistake: Jim Jupiter stays with Peg for a week. 6 days later he's shown heavier than he was before. You don't gain that much weight in 6 days.
Just Married ... With Children - S2-E20
Other mistake: Al gets sat on by 3 heavy women. The scale says 927 pounds. 4 more women sit down and the scale says 1071. So 4 more heavy women only added 144 pounds? Impossible.
Just Married ... With Children - S2-E20
Other mistake: Al and Peg win a new Mustang in this episode. It's never seen again.
Sixteen Years and What Do You Get - S1-E6
Other mistake: Al has his elbow in the caviar yet when he lifts it up out there's nothing on his shirt. Its clean and dry.
Oldies but Young 'Uns - S5-E17
Other mistake: Just before Charlie and his son leave Peg says "Charlie, my watch". Implying that he took it off her wrist. Yet during the whole scene she didn't have a watch on her wrist. It appears in his hand out of nowhere.
Other mistake: Depending on the season the Bundys' address is 9764 Jeopardy Lane. Season 4 the address is 9674. But in the opening credits when Steve is shown on his porch the address is 9674. (00:00:20)
Other mistake: Al eats a slice of pizza. But if you look in the box there's a small piece taken from the center of the pizza. He picked up a full size slice with crust.
Other mistake: Bud calls a late night sex hot line which is a 1 900 number yet he only pushes 6 digits on the phone.
At the Zoo - S4-E10
Other mistake: Marcy knocks at the door, and Steve is inside. He tells Peg to stall her so he can go out the back door. She can obviously hear everything he's saying.
Peggy Loves Al, Yeah Yeah, Yeah - S2-E17
Other mistake: When Bud goes upstairs with his fake bag of "Valentines" (actually a bag filled with bottles), Kelly begins to look through some from her bag. Behind her, you can see David Faustino (Bud) purposely moving slowly up the stairs because Christina Applegate (Kelly) is about to find the envelope that is addressed to Bud.
Other mistake: When Peggy throws the final ball, all the pins fall except for one and the sweep bar comes down. It is then shown wobbling down without the sweep bar in play. This is an illegal drop and would not count under any PBA sanctioned tournament or in any bowling alley in the United States. The bowling alley would credit her with a 299, and Al would have a chance to get a 300.
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.
Other mistake: When Sonya takes off Bud's bandages on his arms you can see they aren't injured.
Other mistake: The Bundys never lock their front door the entire series, but a burglar has to use a crow bar to open the sliding glass door out back.
Answer: It was one of the hoses connected to the engine, nothing specific, but to indicate that Al tampered with the vehicle.