so the code p0156 is which rear sensor, driver side or passenger side?

and what is "Vapor Canister Purge Valve"? what does it do? where do i find it? and how much to fix it? this code is driving me insane

 

bump

 

can someone tell me which sensor on this chart is for code P0156:
http://www.latemodelrestoration.com/...o2-sensor.aspx

 

bump

 

anyone know which 02 sensor i need to replace?

 

sensor two bank two is rear drivers side

 

thanx, im tryin to purchase the sensor from 50resto.com.
http://www.latemodelrestoration.com/....pvx?;sc_step1
i found both rear sensors here, but they're labeled as LH and RH.
so sensor 2 bank 2 rear driver side, is that the left hand side or right hand side?

 

Evap Canister Purge Valve is located in the passenger tire well inside of the plastic paneling. Its $35 or so at Rockauto.com