Pontiac torrent 2006 awd

171 is a bank 1 lean code and 442 is a leak in the evap emissions system I would check around for a vacuum leak possibly at the purge valve near the intake

the 171 code is telling you that there is a lean condition, basically a vacuum leak that affects bank 1 of your engine, on a V6 that would be the side with cylinders 1, 3, and 5. The 442 code is telling you it is in the evap system. a leaky evap line, evap canister, or less likely even a leaky gas tank. If you aren't leaking fuel, the most common cause of this code is a bad or loose gas cap. make sure it clicks a couple of times after you put it on. Also, you could try a new cap. they are not to expensive, and it may fix your problem.