I own a 2006 Accord 4cylinder 5speed manual.
My check engine light came on a few days ago, and i received these codes: p0141 (b1s2 oxygen sensor) and p0420 (catalyst efficiency)
MY mechanic recommended that I start by replacing the 02 sensor. He claims that doing so may eliminate both codes. He quoted me at $200ish for a new sensor with install, which I will probably have someone else do for cheaper, and $450 for used or aftermarket CAT, or ~$700 for OEM CAT. Does it make sense to replace the 02 sensor before messing with the CAT? Thanks in advance for any help!

 

Yes, replacement of the rear O2 sensor may very well take care of both codes. There may be nothing wrong with the cat.

 

Thanks for the quick reply. Does it matter what brand sensor I use?

 

Honda mainly uses Denso brand as OEM O2 sensors. Other brands may work without problems; but, sometimes there are reports of problems. Safer to go with a Denso and Densos actually last pretty long.

The rear O2 sensor will not cause any real drivability problems, so if you want, it can wait a little while you order a Denso sensor through the internet to save some money.

What trim level (e.g., LX, EX) is your car? Also, is this a California car or other state?

 

Since your car is a 5-speed, it is probably a non-California emission vehicle. The rear O2 sensor is Honda part number 36532-RAA-A02.

Amazon has it for $48.10 (Denso part number 234-4797) with free shipping.

"http://www.amazon.com/Denso-234-4797-Oxygen-Sensor-Ratio/dp/B00122EEK2"

Here are links showing install, so you get an idea what is involved:

Replacing Oxygen Sensor - 2004 Honda Accord LX - hondarepairsite

Honda-Tech - View Single Post - 2005 Accord LX 4cyl 2.4 engine O2 sensor

 

I replaced the rear oxygen sensor and the engine light has remained off. thanks for the help

 

Thanks for letting us know.

Glad your problem was solved.

Happy motoring to you!

 

I assume you bought the Denso from Amazon?
I have the same code in my 05 Accord LX 4Dr 2.4ℓ ...
For $50, I'll buy it now instead of waiting for the price to rise (with my luck).
No sense spending more on an OEM part if the Amazon part does the trick!

 

I think I bought it from a chain like napa, don't see any reason not to get from amazon though