97 Accord EX 5spd CEL Code 65 - Please read

[FrostyTech]

Greetings.

The Check Engine Light on my Accord came on this past Saturday.
I did the usual, check gas cap, drive 3 times, reset ECU by disconnecting battery.

None of this helped.
Although, car still seems to run fine.
No clue on a change in fuel economy yet.

I finally jumpered the ECU and got the code..
Code 65 - Oxygen Sensor Heater (Secondary?)

Upon getting the code, I reset the ECU again.
I then proceeded to crank the car and let the ECU flag the CEL again.
It didn't.. I'm guessing the sensor is going bad, but sporatically working.

Would someone please be kind and describe to me whether this sensor is located? Is this the O2 sensor mounted on the top side of the exhaust manifold shortly past the oil pan before the catalytic converter? Or is the O2 Heater a difference sensor?

Many thanks in advance.

[LX-biker]

Originally Posted by FrostyTech

Greetings.

You to.

Although, car still seems to run fine.
No clue on a change in fuel economy yet.

Coz computer "forget" about bad sensor and run with default programm...

I finally jumpered the ECU and got the code..
Code 65 - Oxygen Sensor Heater (Secondary?)

Yep.

Upon getting the code, I reset the ECU again.
I then proceeded to crank the car and let the ECU flag the CEL again.
It didn't.. I'm guessing the sensor is going bad, but sporatically working.

May be bad connection of heater circuit.

Would someone please be kind and describe to me whether this sensor is located? Is this the O2 sensor mounted on the top side of the exhaust manifold shortly past the oil pan before the catalytic converter?

Located on exaust after catalytic converter.

Or is the O2 Heater a difference sensor?

Secondary Oxygen Sensor have additional Heater circuit (Pins 3 and 4 on Mine 98 Accord-sorry if different in yours). You can find wire from O2 sensor, disconnect connector and measure resistance between those pins. Should be between 10...40 ohms. If yes, need to be checked voltage 12v on opposite side when engine is ON. If NO-you need new sensor.

Many thanks in advance.

Luck!!!

[FrostyTech]

Originally Posted by LX-biker

Coz computer "forget" about bad sensor and run with default programm...

Ah, ok, defaults to failsafe settings to keep it running

May be bad connection of heater circuit.

Located on exaust after catalytic converter.

Secondary Oxygen Sensor have additional Heater circuit (Pins 3 and 4 on Mine 98 Accord-sorry if different in yours). You can find wire from O2 sensor, disconnect connector and measure resistance between those pins. Should be between 10...40 ohms. If yes, need to be checked voltage 12v on opposite side when engine is ON. If NO-you need new sensor.

Luck!!!

Awesome man!!!
Exactly what I needed to know.

I just looked underneath and was able to identify the sensor you're referring to after the catalytic converter. Since it's raining here, I'll have to wait till tonight and pull the car in the garage to do the OHM and VDC checks. That's great info man. Many thanks.

So far, after resetting the ECU for the 7th time, the CEL hasn't come back on. I have driven it 4 times since then, which was yesterday afternoon. A buddy mentioned I may have gotten 'bad gasonline' and it freaked out the ECU. I will still do the OHM and VDC checks tonight just for grins. I'll keep an eye on it. If/when the CEL comes back on, ASAP I'm going to jumper the ECU to ensure I get another Code 65.

One last quick question. I priced this Secondary O2 Heater.
OEM = $150 USD, Aftermarket = $65 (entire kit too).
Since I'm probably going to have to replace this in the future, which would you suggest? OEM or Aftermarket?

[LX-biker]

Hi,
Forget one thing:
bad contact in the mentioned connector may be cause too...
About aftemarket depend of brand-some good some not. honestly I not expert with O2 sensors makers, just know few famous like Bosh...
You can try cheapy if labor not expansive or you do byself.

[FrostyTech]

I replaced the Secondary O2 sensor and everything is fine now.

No Check Engine Light, gas mileage has returned to normal, and the engine runs much better than before the heater in the sensor went bad.

FYI: I ended up buying the OEM Denso part from www.alloemautoparts.com for $174 (free shipping)

I searched roughly 2 dozen 'OEM' online parts outlets..
Most wanted $187..

Local Honda dealers wanted $237 (hahaha, no thanks)
Aftermarket with OEM connector wasn't much cheaper than alloemautoparts.

The cheapest being $70 had pigtails instead of the OEM connector.

I've saved myself about $200 total
(Diagnosis, Parts, and Labor)

I'm happy

Thanks LX-biker for the help.
Appreciate it.

[LX-biker]

Nice, Nice!
Congrat!!! & _/\_ for dealers blood suckers...
85$ + tax in Canada for what I did for 1 minute and jumper wire? OOOO that is hi-tech stuff realy....or kids stuff
take care.
Former moto biker.