P0031 code on a new sensor

[couchiedemon]

Hi. I'd welcome some advice for my 2001 H6 Outback. Not long after I bought it I noticed an intermittent problem with the Check engine light coming on (at same time as VDC Off light being illuminated). A quick check with Torque confirmed the error code as P0031 Bank 1 Sensor 1 which i took to be the offside front Sensor (UK). Deleting the code made it go away for a couple of weeks but on hot starting occasionally back it came. So I replaced the sensor last week and cleared the codes. Everything went well for a couple of days.

 

Today the error code came back. Same error code but the description was slightly different  "HO2S Heater Control circuit low (Bank 1 Sensor 1)"

 

Is this likely on a brand new sensor or could it point to a duff connector or something else duff with wiring between the sensor and the ECU?If the latter how would I go about checking.; Any advice gratefully recd.

 

[Dino]

O2 front sensor #1 could be failing the air/fuel ratio. If its done a lot of miles, this is a possibility.

[couchiedemon]

Cheers. The car has done 167k miles. Any idea of a poss solution. I don't really want to Shell out on a 2nd new sensor unless it's necessary. Love the car and want it to run as it should.

[stants]

Can you swap the front and rear over ? If it shifts the code to the one that you know is good then may not be the sensor it's self

[couchiedemon]

That sounds like a plan. I had not thought them interchangeable but I suppose I could swap left and right front to get the same effect. Tks for the tip. will try this tomorrow and see what happens.

[stants]

They may not be interchangeabl, not sen the new age ones but I thought it may be worth a mention to try before splashing more cash

[couchiedemon]

Will try to swap left to right front then and see what happens.

[couchiedemon]

This afternoon I changed back to the previous sensor, ensuring that the connection was extra secure and so far so good.

[couchiedemon]

Success was short lived. The old sensor started playing up but a) not as much as the new sensor and B) only on hot start-ups i.e when the engine was thoroughly up to temperature. I have checked the connector and it looks sound but wonder if there is a further connection upstream between the existing connector and the ECU?