That would be the sensor after the catalytic converter.
knock sensor
I have a 92 s10 blazer and my code 43 was fixed by replacing the knock sensor. so maybe check the knock sensor and the wiring from that to the ECM.
trouble code P0043 means: HO2S Heater Control Circuit Low (Bank 1, Sensor 3)
Trouble code P0043 means: HO2S Heater Control Circuit Low (Bank 1, Sensor 3) Hex code 43 is for a misfire.
no you need the catalytic converter replaced or removed but the o2 has a code of its own which it is P0141 and says the sensor is malfunctioning
any from 88 to 98
there isn't one.
January second, 1943
code 43 except2.2or2.5 4flashes pause 3flashes electronic sparkcontrol knock sensor circuit probable cause faulty knock sensor or mem_cal.
knock sensor
probably the ignition switch if you are refering to the starter solenoid.
code 43 is related to the spark control system. (esc) the problem is usually the knock sensor wiring connector is defective and/or the sensor. the sensor is located in the right /passenger side of the engine block near the starter.