P0053, now P0171 and P0174

[cashville]

I had the P0053 code, which is HO2S Heater Resistance (Bank 1, Sensor 1).
I bought 2 O2 sensors from New Global Automotive (http://www.ebay.com/itm/170884100778...4.m1497.l2649), and replaced 1 from each side (Bank 1 and Bank 2, although Bank 2 didn't point any errors, I went ahead and replaced it anyway).
I cleaned up the error with an OBD2 machine, but after about 10min I got the engine light again. I read them, and the error I get now is P0171 and P0174 (which are System Too Lean (Bank 1) and System Too Lean (Bank 2).

Before switching the sensors the 171 and 174 never showed up.

I don't know if these errors are coming up because the sensors are not OEM, or if they are showing up because the sensors are now reading the information correctly.