drone6

VSC, Check engine light just came on my GS300. I only have 50k miles on it. I had this happen a few years back and it was the Gas cap o-ring. This time I changed the gas cap and reset the codes but no luck.

After starting the car, with a minute the lights come back on. So checked the code and here is what I'm getting:

P0031
Heated Oxygen
Sensor Heater
Control Circuit Low
Bank 1 Sensor 1

Doing a search for the code yields this: http://engine-codes.com/p0031_lexus.html

Any thoughts from you guys on changing the sensor vs. checking something else that might be the issue?

Please help.

SILENTM

You could always try switching the front O2S and see if the fault follows the sensor. If no other codes i'm pretty sure its the sensor itself.

drone6

So where are the O2 sensors? Any diagrams?

I was looking on the sewell lexus site but having hard time locating the sensors.

BinaryJay

Look at the exhausts. Find the catalytic converters (easy to spot), slightly upstream of them you'll find the A/F Sensors.

drone6

It's been a few days since I replaced the gas tank cap - and as of this morning all the lights are gone and the code is cleared by itself.

I didn't want to order the sensor till I knew I could do the swap myself - so it all worked out.

10 dollar fix, hopefully that was all :-)

Thanks for the input to SilentM and BinaryJay.

momodballe

what was the issue? Was it the actual gas cap?