Hello. I have an volvo v70 2.0T 2000mod, the engine runs fine until i press the throttle too hard. Have changed coils and spark plugs etc.. Need help please! And what does that B1S12 mean??

 

O2 Sensors are categorized by their location - Bank1 sensor 1 refers to the front sensor in an I4 or I5 engine. V engines or engines with 4 sensors (like the S80s) will have Bank1 and Bank2 to differentiate left and right