so last week i was driving and check light came on so i did the on off on off on trick and it displayed p0137 the next day it was gone i week later check engine anagin p0137 on the way to work but i got in to go home and it was gone again what does this mean??

oh if it helps it came on both times doing 80KMH and around 1500--1750 RPM

 

O2 Sensor,I think. Not sure which one off the top of my head, but check google, it will tell you.

 

Oxygen O2 Sensor Circuit Low Voltage (Bank 1, Sensor 2)

Thats the drivers side, rear O2. Cost is about $25-30