Is DTC P0141 Secondary HO2S (Bank 1 Sensor 2) Heater Circuit Malfunction usually associated with loud uneven engine noise?

Apr 14, 2021
No experience with oxygen sensors, but noticed the first step in a service manual was clear the code and see if it comes back. So wondering if that only makes sense for a "silent" malfunction - just the warning light.

Started the '04 Acura TSX tonight and it was unexpectedly loud and rough, so turned it off rather than wake the neighbors. Before the days of electronics would have just presumed time for a muffler, but the malfunction indicator light was on, and got DTC P0141 with a basic code reader. I'll try to look underneath the car tomorrow if the continuous rains stops. And perhaps run it a few minutes to see if it calms down as things heat up.

Will have to use a pro, but if it's not a bad electrical connection, looks like prices are all over the place for that part, from $22 generics to over $400 from Honda.
That is an O2 heater circuit code on bank 1 sensor 2. That O2 sensor would be after the cat and is saying that the heater portion of the sensor is not working. You need a graphing scanner or a scope to really see what the sensor is doing.

If replacing it, I would definitely go with OEM on these because I have not had good luck with aftermarket O2's on the vehicles I have used them on.
>Someone steal your catalytic converter?
...did say in the original post that I plan to look under the car tomorrow...

>I would definitely go with OEM
Well do hope to keep the old car going a while longer.

>Large exhaust leaks near the O2 can skew it's output.
Interesting. Especially because of the noise, I had wondered about that. Whether or not I can see anything in the light tomorrow, I'll be taking it to be looked at. The only other check I can maybe do here is measure the heater element resistance - if there is an easily accessed under seat connector.

And thanks for the comments.
The only symptom of failures that cause the P0141 code is the CEL and code itself. The operation of the car is unlikely to change at all.

Something else has happened such as a broken pipe or stolen converter with attendant cut or unplugged wires. The heater circuit code indicates an electrical fault, it is not an issue of gas composition.
Thanks for the extra note. Didn't stop raining so will try to get a look under tomorrow, but of course will be taking it in to be checked.
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Looked today.

Unless the pipes rusted through on both sides of the catalytic converter and burst through the heat-shield while the car was parked, and it fell off and rolled far away, the P0141 is explained as mentioned above.

Admit I'm morbidly impressed. Must have been fast and quiet. And there's less than a 3 hr window between the late-to-bed and early-to-rise with the sun crowd around here this time of year.


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