I recently changed oil in a 2006 Pontiac G6 and the owner asked me a question about her air conditon. She bought it from a dealer and her air seems not to blow cold. I ran the car , a/c on , compressor kicks on normally (no cycling) but it blows hot in drivers vent, simi cool in middle dash vents and kind of cool in passanger vent. Any ideas?

Have her run on-board diagnostic tests on the electronic air control. It may be a similar process to that below:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-11.html#post1999642