Help With ODB II Codes

Ok so I just tried to smog my Jimmy. I knew it would fail due to the check engine light being on. Does anyone know what these ODB codes are.
P0141-O2 Sensor Heater Fault ( Bank 1 Sensor 2)
P1406
P1870

Are they a simple fix. The guy at the shop told me for $295.00 he would gaurantee it will pass smog. Does that sound right or is he trying to rip me off.

Any help or suggestions would be appreciated.

Yeah right, the sensor is issue is the heater circuit wiring or sensor, 1870 is trans slippage codes, could be a significant problem, 1406 is egr postion error, no way to fix all this for 295, unless some hanky panky is afoot.