Hey i kind of need some help i just recently purchased a cobalt from an auction and have been very happy with it. About 2 months ago i got a CEL, and took it to autozone to get the code checked and i was told that it is error P0171, which the clerk said was a up stream oxygen sensor. So today i finally have some extra cash and time to fix the problem and open up the engine compartment and i find that the air intake filter has been moded and quite frankly looks like shit (pics at the bottom). So i have been trying to find some good diy but most of the ones on here pictures wont load so i am not sure if this is a good job or a bad job or i am not sure if i should redo it or not. So i was also wondering if this make shift air intake could be to blame for the code, or if it is really the 02 sensor. And if it is the o2 if someone could point me in the right direction of a diy for replacing the o2 that would be awesome.