Engine Controls - MIL ON/DTC P0141
MIL On With DTC P0141 in '03 Accord L4sGot a '03 Accord L4 in your shop with the MIL on and DTC P0141 [secondary HO2S (sensor 2) heater circuiti set? Check for poor connections or wire damage to the heater circuit. If the circuit is OK, then replace the secondary 02 sensor, and clear the DTC.
The sensor may have gotten damaged from internal corrosion to the sensor heater. You'll most likely run into this problem if your service customer lives or works in one of the salt belt states. The replacement sensors in Honda parts stock have been updated to prevent this problem.