A quick google search pulls up those codes relating to the MAF and Oxygen sensor. I would say clean your MAF with that cleaner they sell at most autoparts, should say "MAF Cleaner" or "Mass Air Flow Sensor Cleaner". Since the MAF's probably dirty, check your air filter - it might have failed, which isn't a good thing. Now why your car doesn't start might have something to do with an electrical problem, but cleaning the MAF and checking the air filter doesn't hurt, and is relatively cheap. On a side note, those trouble codes are "P0131" and "P0171", containing only the letter "P" and a four digit number, not "Po" and three numbers (That would prevent them from coming up on Google as trouble codes).
Out of curiosity, how did you get the codes out? I use a bluetooth OBDII adapter, and use free software which gives me a brief description of the code.
EDIT:I just saw your other posts and do suggest that you inspect everything before throwing parts at the car, as that can be quite expensive. The trusted mechanic is a very good idea, if they're a good mechanic, they'll tell you what's wrong before the fix it, and not rip you off. I'm an avid DIY'er and love to work on my car, but if and when stuff gets out of my league, I've got a (hopefully) good mechanic that I trust. Oh, and Good Luck!!
