O2 Sensor Replace - p0031 Code?

[07limitedV8]

I have a 2007 4Runner with V8. Current mileage is 36k.

The check engine light came on along with the VSC lights.

I pulled the codes and the only code that comes up is p0031; which is the Oxygen (Air/Fuel) Sensor Heater Control Circuit Low (Bank 1 Sensor 1). I reset the codes with the scanner and the engine light immediately comes back. Later I pulled the EFI and EFSC fuses from under the hood and after a several minute wait replaced them. This caused the check engine light to reset and I was able to drive around for a day before the check engine lights returned.

I'm concerned that this sensor has failed prematurely, but I've been driving this car in Ukraine for 9 months. The gas quality here is not the best and the roads are terrible; and this truck gets bounced around a lot. What are the possibilities that this isn't just a faulty sensor?

I visually inspected the sensor. Driver side/Above the Cat. I couldn't see any worn wires or anything out of place.

<a href="http://s301.photobucket.com/albums/nn64/sushiman2000/?action=view&current=O2sensorreplace.jpg" target="_blank"><img src="http://i301.photobucket.com/albums/nn64/sushiman2000/O2sensorreplace.jpg" border="0" alt="Photobucket"></a>

Can I check this sensor with an ohm meter? I read somewhere that I can check the two black wires for 16 ohms.

Can I drive the vehicle around with the electrical connector unhooked while I wait for the new part to arrive? I heard that the electrical connection is a pain to unhook and I'd rather only do it once if it's so difficult.

Does anyone have a tip on how to remove the electrical connection easily?

If I find that the sensor is in fact faulty, I plan to buy the Denso Upstream O2sensor Toyota# 89467-7100 or cross reference Denso# 2349051.

Should I plan on changing all the O2 sensors at one time? GD that would be expensive and a lot of work.

Am I on the right track?

 

[Acidmeld]

Just replace the one sensor. The heater element inside the sensor has gone bad. It was probably being used more often with the bad gas. The sensor is still reading once the exhaust gets it up to temp but at startup will take longer to go into closed loop control. Leave the sensor plugged in until you replace it. You do not need to replace all the sensors at once. Replace them as they go out. Be sure to use oem parts.

Step 1: Buy sensor
Step 2: Replace sensor
Step 3: Enjoy a cold beer...:cheers:

 

[trdsport]

Hey
Though its an old thread, am having the exact same issue on my 2005 4.7L v8, changed the bank1 sensor1 O2 sensor(denso) still having the same code & VSC lights ON. Wonder how you got rid of it.?

 

[cice]

I'm having the same issue, replaced the o2 sensors on my v8 with Denso sensors from Amazon. Now I have the P0031 code... Any ideas?

 

[oldboy]

I had this P0031 code just last week on my 2004 v8. Looked up the part number using the Denso “Find My Part” tool located here

Find My Part

I ordered the upstream sensor from Amazon and installed it. The code instantly cleared, without my having to clear it, when I started my vehicle.

Different engines and years take different parts. Were the correct parts for your vehicle(s) ordered?

Lou

 

[cice]

Thanks for the quick reply Lou. I replaced both with two of these from Amazon. Amazon.com: Denso 234-9051 Air Fuel Ratio Sensor: Automotive

Only the bank 1 sensor seems to have the issue (P0031). Perhaps I just got a defective sensor? It doesn't seem like I could have damaged anything replacing it, but then again a defective sensor seems odd too... The sad part is I actually replaced them as a maintenance item since I hit 184k miles.

 

[oldboy]

Not sure what year/engine you have, so can’t check the part number. I think
The probability of getting a bad new part is low. If the old one was working without a code, I would reinstall it.

The front ( pre-cat or upstream) sensor is usually different than the rear (post-cat or downstream) sensor.

My 2004 v8 took this part for the upstream sensor.

Amazon.com: Denso 234-4138 Oxygen Sensor: Automotive

Lou

 

[cice]

Well, turns out the sensor off of Amazon is the correct one for a 2007 V8 and it was working fine. The issue was the installer (me) who didn't push the plug in all the way until it clicked. I pushed it in all the way and the problem is gone!:redbrick:

Thanks for everyone's help!

 

[oldboy]

Glad that worked out for you!