Plot hole: Notice when Steve joins the card game. He looks at his cards and says I'm in. The cards are face up on the table! And for some reason the other players have one card facing out where others can see it.
Revealing mistake: Peg is making popcorn on the stove. It pops even though the burner isn't even on.
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.
Weenie Tot Lovers & Other Strangers - S5-E18
Revealing mistake: When Peg opens the last weenie tot box, notice that only a ticket falls out. Meaning all the boxes had no tots in them just tickets.
Kids! Wadaya Gonna Do? - S5-E19
Continuity mistake: Bud comes in the house after telling the old lady to get lost. The door doesn't shut completely. Kelly says open the door open the door. Bud goes to the door and it's shut even though it was open a crack from him not shutting it before.
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)
Revealing mistake: When the chain is cut from Al's wrist, you can see and hear that it's plastic not metal. (00:02:28)
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.
Revealing mistake: Kelly is making popcorn on the stove. It starts popping even though the heat isn't even on.
Requiem for a Dead Briard - S10-E3
Continuity mistake: When Peg is comforting Kelly about Buck passing away, she is holding a bag that says "Petropolitan" on the front. The next shot when they go back to her, all a sudden the words are gone from the bag she is holding and Bud is holding a bag with those words.
Continuity mistake: After Kelly breaks the TV screen, each time the camera changes, the broken screen looks different each time.
Visible crew/equipment: Right after Jefferson walks out after saying what he was in jail for, when they are showing Bud and Al, you see a large head shadow go across Bud's leg from left to right.
Revealing mistake: When they blow up the scoreboard at first in slow motion, the entire scoreboard is blown up and destroyed. The next shot only a small portion at the top and middle is destroyed, not the entire thing.
Cheese, Cues and Blood - S6-E4
Continuity mistake: When Kelly shakes her head no to the guy she is playing for $10,000, he misses the shot and the ball stops at the far end of the table. When Kelly goes to take the next shot for the win, she is hitting the cue ball from the other side.
Breaking up is Easy to Do (2) - S11-E15
Revealing mistake: When Al falls on the bed with the shoe and puts the hole in the water bed, the shoe doesn't hit the bed anywhere near where the water starts to shoot out from.
Every Bundy Has a Birthday - S7-E3
Revealing mistake: At the park when Al hits the rich man, he goes down like he was knocked out. Soon after, Seven punches the kid. In the background the rich man is actually sitting up on his side and he looks at Al and Seven, then as the camera pans towards him, he lies down on his side like he is passed out again.
Revealing mistake: While they are jousting, there is no one at all next to the stage in the wide shots. Every time they show the stage up close, there are 40-50 people. It changes back and forth the whole scene.
Continuity mistake: At the airport outside, Marcy yells at Jefferson and knees him. While she does that, there is a man wearing a white coat walking behind them. Camera instantly changes and there is no man at all in a white coat. In fact, there is now a woman wearing a white coat.
Poppy's By the Tree (1) - S2-E1
Continuity mistake: Bud asks to go down to the high school "tomorrow" to meet the man who met Andy Griffith. Earlier Al reads the events page in newspaper. The event was said to be "tonight."
Girls Just Want to Have Fun (2) - S2-E6
Continuity mistake: When sitting on sofa with Marci, Peg's necklace falls beneath her red blouse. It remains under in most shots, but in the last shot it is outside her shirt.
Answer: It was one of the hoses connected to the engine, nothing specific, but to indicate that Al tampered with the vehicle.