02 Bank 1- Sensor 2 - Oxygen Sensor Voltage Low

[Zelf24]

Hey all,

So a while back my 2002 Accord EX V6 began having trouble starting when hot, and didn't give any trouble when cold. It was throwing code P0116, saying that the engine coolant temperature sensor was bad, so I replaced it and all appeared to be well.

Things were fine for about two weeks, until the same issue started to occur again. This time, with no codes. I took out my trusty BlueDriver and while the car didn't report anything blatantly wrong, a look at the live engine data showed me that the "O2 Bank 1 - Sensor 2 - Oxygen Voltage" was super low, when compared to Sensor 1. I'd say that Sensor 2 was getting 1/8 of the voltage that Sensor 1 was getting. All other data with the car appeared to be normal.

Does anyone think that this low voltage has any correlation with the way my car is behaving? Do I need to replace Sensor 2?

Thank you so much.


Upon further reading, would a failing main relay sound like a more logical culprit?

 

[james'99]

The seconday O2 sensor has little to nothing to do with how the car runs. I would replace the sensor, but I don't think that it will solve anything besides the CEL.

 

[xci.ed6]

Was the engine hot?

What were the actual voltages?

Starting when hot, check the fuel pressure.

 

[Zelf24]

I've replaced the main relay, as a faulty one appears to be attributed to a lot of "hot start" problems. So far, knock on wood, no issues through various states of operation.

xci.ed6 - If I have a chance this weekend, I'll get that data for you. Thank you all for your help!

 

[xci.ed6]

I'm just a bit suspicious of fuel pressure, since mine got down to like 35psi. It was high enough there was no CEL, but low enough it didn't like to start when hot.

 

[Zelf24]

I just wanted to add some closure to this issue in case anyone comes across this thread in the future:

It appears that my hot start issue was attributed to a faulty idle air control valve. I started up my car to go home from work and the RPMs were fluctuating like crazy. It was almost like a stuck/unstuck accelerator, as when I was in gear, the car wanted to jolt forward. I wound up riding the brakes all the way to my closest Honda dealer, and they diagnosed the problem as being the idle air control valve.

$400 later (dealer parts/dealer labor), my Honda is 100% back to normal. No more issues with stalling, or hot starts anymore.