At the opening of her photography show, Marion, the high-strung heroine of “2 Days in New York,” has an awkward encounter with a critic. Frustrated by his noncommittal responses, and stressed out by everything else going on in her life, Marion (Julie Delpy) launches into an unhinged, obscene tirade at the man. Later in the film a karmically empowered pigeon drops an airborne excretory insult on him.

“I like the theme more than the execution,” the critic says, and this is more or less how I feel about “2 Days in New York,” a sequel of sorts to Delpy’s “2 Days in Paris.”

There is great charm, and considerable insight, in her ideas about romance, cultural misunderstanding and daily life in a modern metropolis. There are also moments of marvelous comic exuberance and lovely caught-on-the-fly glimpses of Manhattan without its makeup. But the film succumbs to the chaos it depicts, and so undermines its best intentions. It is, all in all, a likable mess.

Which goes for Marion, too. In the earlier film, she traveled to Paris with her American boyfriend Jack (Adam Goldberg), who was hit with a barrage of her nutty kinfolk and former lovers. Now she and Jack have split up after having a son together (a sweet-faced toddler named Lulu), and Marion lives with Mingus (Chris Rock), a journalist and radio host who has a child from a previous marriage.

The harmony of their cozy household is disrupted by the arrival of three of the noisettes from “2 Days in Paris”: Marion’s father, Jeannot (played by Delpy’s father, Albert); her sister, Rose (Alexia Landeau); and Rose’s boyfriend, Manu (Alex Nahon). They proceed to drive Mingus and Marion crazy.

The best parts of “2 Days” are those that cast an affectionate, unsentimental eye on the city, which looks lived-in, real and nonmythical.

The driving-crazy part is hilarious and persuasive, partly because Delpy and her cast depart from the usual caricatures of Frenchness while still engaging in broad, silly satire.

A not-so-good part is that Marion and Mingus never quite seem like a credible, comfortable couple.