CEL Code P0139
 

Hello Gurus of 986forum

So far after the last meltdown incident all seems to be well. The car runs cool, the tank doesn't leak, no intermix, and generally all seems well after about 250 miles. I replaced water pump, thermostat, flushed, and put in new unicorn tears.

But, (always a catch) I am getting a P0139 fault code. From what I have learned from my research, this is the O2 sensor behind the cat on the passenger side. This would make sense as this sensor was doused by the overflow hose on numerous occasions.

I just want to confirm that this is the correct diagnosis and it looks like a pretty simple fix, if it is.

Thanks!

Get the O2 sensor removal tool sold by Pelican and use a 3/8" breaker bar. Mine ca,e out without any trouble. Make sure you apply or already have bought sensors with high temperature anti seize compound on the threads. You will thank me next time they have to come out.

Pelican is closed over the weekend.
Is it ok to drive the car until I replace it?
From what I understand this sensor is for emissions and not performance, but I don't know if that's true or not.

I know you're a little fun shy but your car will be 100% fine to drive. I'll bet you can clear the code and it may go away for quite some time...try it, see how long it takes to come back! Don't sweat this one.

Great..thanks for that.
I've actually been punching the car around a bit and having a lot of fun with it again.
This can wait 'till next week then!

+1 To what dghii said. No worries driving it. The sensor before the catalytic converter is important. Your engine computer uses it to compute the proper ratio of fuel:air. The sensor after is for detecting the efficiency of the catalytic converter and has no function other than monitoring emissions.

If you want to confirm things, swap the driver and passenger side O2 sensors, drive it, and see if the code follows the sensor. If you order the part tomorrow you'll be good until it comes in. (edit: I misread, I see now that it's the post-cat sensor - that's even less important)

Agree that the O2 socket tool is helpful and worth it.

I am happy to report that changing the sensor turned off the "Check Expenses Light" and the car is running great!
Thanks for the help!