i have a 98 civic dx and the check engine light came on the trouble is
P0141 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2) ?
what that mean the O2 sensor or a heater sensor

 

for oxygen sensors to work properly they need to have a constant temp. thats why they have an internal heater. the code is for a heater circuit malfunction. basically, what usually happens, is the heater burns out in time causing an open in the circuit. when this happens, the ecu looks for a voltage drop saying that the heater is using the voltage. if it isnt, the ecu knows there is a problem with the heater. you can ohm the heater circuit in the sensor, but i am about 99% sure replacing bank 1 sensor 2 oxygen sensor will fix it.

the bank 1 sensor 2 is the sensor after the cat.