Y4 730 then UA 4009 at Houston
Mexico City → Houston → El Paso
Timetable, Houston time
08:04Y4 730 from Mexico City at the gate
20:10UA 4009 to El Paso leaves the gate
12 h 06 apart on the timetable
UA 4009 leaves 12 h 06 after Y4 730 arrives on the timetable: more than half a day, so not a connection we count.