The error code on this Honda is P0141. This is the code for fault at the second oxygen sensor, the sensor is not heating properly. Fortunately, this code almost always means the oxygen sensor is bad, unlike many other codes where something else on the engine is causing the problem but blaming the O2 sensor.
You will need a 22mm wrench to replace the oxygen sensor.
If your check engine light is on, but you don't have an OBDII scanner to read the code, you can go to most autoparts stores and they will read the code for free. There is no need to go to the dealer to have the code read. When the auto parts store reads the code, be sure to write it down so you can research it. Chances are the auto parts store will not clear the CEL code. If you would like to clear the code yourself, you can disconnect the battery for about 15 minutes, then reconnect and see if the check engine light is out. Some codes will not clear until you fix the problem, this P0141 is a prime example.
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