Hyundai Repair: Hyunday accent, oxygen sensors, charcoal canister

Question
I just bought a 2002 Hyundai Accent, 1.5 AL, manual Trans, it has the "check engine" light on, I took the car to Autozone and in the presummed causes is the oxygen sensor, they showed me the part, and they told me that it could be next to the catalyst, if this something I can do, if so, how do I do it, and I'm having a big problem trying to fill up my gas tank, it's like it's full of air, the gas pumps always stops, not even 1 gallon I can pour, well I have to do it with a lot of patience and little by little, what could be the problem? it's driving me nuts, it takes me like 25 min to fill up the tank. Thank you in advance for your help.  Regards

Answer
If you've got basic tools and the ability to use them, you can replace your own oxygen sensor.  You may, however, desire to purchase a specially designed oxygen sensor socket, depending on the location of the sensor you wish to replace.  Although the exact position of the oxygen sensor varies by the emissions package your vehicle has, most 2002 Accents have one in the exhaust manifold and one in the front exhaust pipe.  To replace, you'll need to use the socket or a 22mm wrench to unscrew the sensor (after unplugging).  

If you follow up with the code that was set, I can provide additional details on diagnosis and repair.  In many cases, oxygen sensor codes don't necessarily mean there's a problem with the oxygen sensors themselves.  I've seen many vehicles where the actual problem was with the programming of the engine control module (ECM) or was an exhaust leak.

Your issue with filling the tank is not related to an oxygen sensor (not sure whether you knew this).  This issue occurs because your fuel vapor management system cannot properly vent the vapors through the charcoal canister to the atmosphere.  This is most frequently due to a clogged canister or canister filter, but could also be due to any sort of blockage in the fuel entry path or the vapor vent path.