Auxiliary Emission Controls (P1403/P1402)

hi! i'm new. my "check" light has been on in my car for a couple of weeks. i took it to AutoZone, and they told me it had something to do with the Emission Controls. Grease Monkey told me i needed to replace my PCV valve. so i did that. but the light is still on. so i took it to Advance Auto this morning, and the following DTC codes came up:

P1403
Manufacturer Control
Auxiliary Emission Controls

P1402
Manufacturer Control
Auxiliary Emission Controls

can someone please tell me what this means and what i can do about it? thank you SO MUCH.

Elisa

p.s. i drive a 2001 Accent GL.

It's probably one or both of your O2 (oxygen) sensors. Take it to a Hyundai dealer...They can read the codes free-of-charge. You can probably replace the O2 sensors yourself with little to know mechanical knowledge.