I'd still like to know the exact code. THere are several associated with the Secondary Air Injection system. BUT, anyway, no failure in the secondary air will cause the car to not run right - secondary air is air injected into the exhaust at cold startup to head up the cats.

Stalling going into passing gear or from 1st to second sounds very odd to me. Does the car idle well? I'd suspect MAF (which also contains the IAT - intake air temp sensor) - try removing it and cleaning it (per one of the youtube videos on the subject) other than that, I'd kinda suspect the Throttle body. A lady near me had odd hesitations on the highway, and the car didn't always start easily -but it idled fine. A replacement throttle body fixed it.