Thanks for the info. I'm using Torque (Pro) with an ELM327 OBD bluetooth device , I can't seem to see lambda sensor voltage as an option so I don't think the app or OBD device support it.
I'll order the first Lambda sensor and see if the code reappears after clearing.
Car felt very lump and hesitating under part throttle , then seemed to be fine, then again it hesitated worse - full throttle and higher revs it seemed to be fine again but then all of a sudden CHECK EMISSIONS light illumunated. #
OBD reader has 2 codes:
P0135 - 02 Sensor Heater Circuit...