Apu says that he memorized Pi to the forty-thousand digit, which is one. This is actually correct. 
Marge's inmate number is 24601. This is also Sideshow Bob's number, itself a reference to Jean Valjean from Les Miserables.
Lisa says her dress is red despite the fact that it is orange.
Marge was convicted of a misdemeanor. She would have served her sentence in County or City Jail, she would not have been housed in a prison (state and federal institutions) alongside convicted murderers and other felons.
The title of the episode is a possible reference to American rock band Alice in Chains.
Flanders blames his kids getting sick on God punishing him for watching Married...With Children. Married...With Children was, like The Simpsons, a FOX sitcom about a down-and-out, dysfunctional suburban family. Unlike The Simpsons, Married...With Children was a live-action show, had stronger sexual jokes, a more cynical take on modern life, premiered the same day FOX premiered as a channel (in 1987), and ended after a ten-year run. The joke in which Peg compares the lifeless and limp plants to Al's bedroom performance were the kind of jokes that were heard on the show.
Tattoo Annie has a tattoo on her back with Alfred E. Neuman on it. The tattoo references MAD magazine fold-ins and the phrase "What Kind Of Slime Would I Marry?" folded in reads: "What, me worry?", which is Alfred E. Neuman's trademark phrase.
Lisa says, "It seems like I've been wearing this same red dress forever!" This is a nod to the fact that Lisa is wearing the same red dress in almost every episode.
When the foreign workers are loading the Juice Loosener, the silent cut is quite likely an audio gag in reference to voice translations often being longer or shorter than the foreign speech it replaced.
Maude watching Marge through a crack in the wall hidden by a picture is a reference to Alfred Hitchcock's movie "Psycho".
The Jimmy Carter statue's plaque has the words "Malaise Forever" (later modified to "Marge Forever" alongside the statue), a reference to Jimmy Carter's infamous Malaise Speech.