[Jaggy_233]

I got a check engine light last week. Took it into autozone and found

"Code P0247 indicates that the Bank 1, Sensor 2 O2 electrical circuit signal had low voltage for a predetermined period of time.

P0137 HO2S Circuit Voltage Low
P0137 HO2S Circuit Voltage Low"

I did some research on it before doing a 5 hour long trip and saw it wasn't critical. The check engine vanished a day after the trip.

Does this help in diagnosing the problem? I was going to use a multimeter to test the circuits, before buying specific parts for replacement.

 

[jiantao]

See if it comes back first. Sensor 2 is after the catalytic converter, I believe. I've had a P0136 code on my Toyota for awhile that I'm just ignoring. It doesn't really harm anything.

How many miles do you have? It's likely that the O2 sensor just needs replacement.

 

[Jaggy_233]

See if it comes back first. Sensor 2 is after the catalytic converter, I believe. I've had a P0136 code on my Toyota for awhile that I'm just ignoring. It doesn't really harm anything.

How many miles do you have? It's likely that the O2 sensor just needs replacement.

175k miles. Still hasn't came back on.

 

[jiantao]

175k miles. Still hasn't came back on.

Yeah, I would suspect the after-cat O2 sensor needs replacement. Don't worry about it if the check engine light doesn't come back. If the Sensor 1 goes bad, which is the air-fuel sensor, that can cause an improper ratio of air to fuel to be dumped through the catalytic converter. Sensor 2 isn't as important IMO.

I've heard of some folks changing the O2 sensors as preventative maintenance around 100-150K miles. That's about all they tend to last, anyway. It's not a bad idea. If you do change the Sensor 2, change Sensor 1 as well.

 

[Jaggy_233]

I imagine either way it would adversely affect a smog test.

 

[Jaggy_233]

Yeah, I would suspect the after-cat O2 sensor needs replacement. Don't worry about it if the check engine light doesn't come back. If the Sensor 1 goes bad, which is the air-fuel sensor, that can cause an improper ratio of air to fuel to be dumped through the catalytic converter. Sensor 2 isn't as important IMO.

I've heard of some folks changing the O2 sensors as preventative maintenance around 100-150K miles. That's about all they tend to last, anyway. It's not a bad idea. If you do change the Sensor 2, change Sensor 1 as well.

It might be worth mentioning that this could affect the smog test.

 

[robtwalsh]

I got a check engine light last week. Took it into autozone and found

"Code P0247 indicates that the Bank 1, Sensor 2 O2 electrical circuit signal had low voltage for a predetermined period of time.

P0137 HO2S Circuit Voltage Low
P0137 HO2S Circuit Voltage Low"

I did some research on it before doing a 5 hour long trip and saw it wasn't critical. The check engine vanished a day after the trip.

Does this help in diagnosing the problem? I was going to use a multimeter to test the circuits, before buying specific parts for replacement.

I changed both oxygen sensors on my 2004 Odyssey. It is imperative that the first, forward sensor be the Honda OEM part by Nippon Denso.
which you can get from Amazon.
Do not install any other alternative part as this sensor performs 2 critical functions. This is mandatory.
Any alternate part will cuase problems such as yours.

 

[surgeon]

Denso or NTK are preferred for Ody.

P0134 code where to buy O2 sensor

Looking to replace the upstream bank 1 O2 sensor myself this weekend. Any suggestions for brand and good places to buy with better prices than what I'm finding. So far I see Denso's at $199 and Bosch & NTK at $100.

www.odyclub.com

 

[thscott]

I changed both oxygen sensors on my 2004 Odyssey. It is imperative that the first, forward sensor be the Honda OEM part by Nippon Denso.
which you can get from Amazon.
Do not install any other alternative part as this sensor performs 2 critical functions. This is mandatory.
Any alternate part will cuase problems such as yours.

Do not buy from Amazon or eBay. Lots of counterfeit parts sold there. Rock Auto would be a safer source.

 

[jiantao]

It might be worth mentioning that this could affect the smog test.

If it's functioning fine enough to not cause the check engine light to come back, I think you should be able to pass smog without an issue.

If it's a finnicky sensor, you may still be able to pass smog by resetting the codes and having it tested after the computer gains sufficient data but before the sensor throws a check engine light again. Although, you may have to change the sensor in order to pass if the code comes back in a short amount of time.