I started my car (03 Accord Coupe EX 4-cyl, automatic) this morning and the CEL light was on. I took it to AutoZone and they told me that it was coming back as a P0141, which meant my O2 sensor is malfunctioning.

Are there any more diagnostics I can perform to make sure that the O2 sensor is the problem? Or is it safe to take their word for it and replace it.

Can I replace this part myself? I'm not proficient with car maintenance, but can handle basic stuff.

 

Jimblake posted this in another thread on 5/28, so I'm plagiarizing:

"P0141 is for the rear sensor, the one that's actually screwed into the catalytic converter.

Unplug the sensor (that plug might be inside the car, under the passenger seat).
Measure resistance between the 2 same-color wires (black?) and a bad sensor would probably read open-circuit. I think it's supposed to read something like 10 ohms if it's good. "

-Type in "P0141" in the search function above and you'll get loads of results.

 

That code indicates a problem in the Heater Circuit of the Sensor;[bank 1 sensor 2 ] and yes it will need replaced if the heater circuit is not working.
First check fuse #6 - 15amp in the drivers underdash fuse panel [cruise control]
Then you can go to the O2 sensor plug and check the resistance on the #3 and #4 terminals; [see pic] There should be 5.0-6.4 ohms resistance.
Also on the corresponding terminals of the wire harness side of the connector, there should be 12V when the key is turned on.
The Sensor needs a special socket to remove it, most parts store have them or loan them.
I strongly recommend you stay with an OEM or 'Denso' sensor.

 

Beginning in 2003 the sensor preheaters have a different wattage vs. most earlier Hondas.

According to 2003-2006 Helm book...
Front sensor heater resistance spec. is 2.1 to 2.9 ohms.
Rear sensor heater resistance spec is 5.0 to 6.4 ohms.

 

So since I do not have equipment to measure ohms, then I'll need to bring it into a shop right?

 

A multi-meter would be a really good thing to have in your tool box.

 

multi meter. Like this thing?

http://en.wikipedia.org/wiki/Multimeter

 

Yep. You can pick on up at sears or wal mart for <$20.

 

Yeah, you can buy one for less than the cost of one hour of shop labor. Then you get to keep the meter.

$20 meters aren't real accurate for measuring low resistance like 5 ohms, but so what...
Sensor heaters usually fail completely, so the reading will be WAY WAY off. Not just a little bit off. And you'll have the tool for future use with dead batteries, flaky alternators, etc.

 

thanks guys, I'm going to try to replace this myself.

Do you know if there are diagrams of where this part is online?