Could penetrating oil damage AF sensor?

[jason214]

I replaced the fwd donut gasket yesterday.

Noise is gone and now I have multiple different codes for Bank 1 Sensor 1.
I metered out the sensor as per manual and the sensor is shorted between pin 1 and 2 and open between 1 and 4. The exhaust stinks badly when engine's running.

I had sprayed flange bolts prior to replacement for a few days and I got some penetrating oil (Seafoam deep creep) on AF sensor by accident while I was spraying LH bolt from top.

The car has 130,000km (81,000 miles) and the sensor is original. A Denso 234-9052 is on its way from Rockauto.

Did anyone have the similar issues before?

[CoryM]

Not unless you sprayed it into the sensor itself. And even then it would likely be fine. Probably just got bumped around while it was on its last bit of life.

[ezhacker1]

You took off the exhaust header to do the downpipe donut? What are the codes car is giving?

[jason214]

Yeah, it might have been on its way out.
I replaced the donut gasket by removing two flange bolts with springs.
I had p2195 and p0171 before I replaced the donut gasket. Now I have a different code that I cannot remember. I'm currently away from home.

The only thing I had done to the sensor was spray it with Deep Creep when it was warm. I couldn't see where I was spraying.

[B.B._07]

A P2195 code is an O2 sensor code and a P0171 can be caused by a failed O2 sensor, so I think it's safe to say your sensor was gone before you touched anything. Penetrating oil won't hurt an O2 sensor which is designed to withstand extreme heat.

[jason214]

I replaced the A/F ratio sensor today. I did it from underneath the car using a 7/8" torque adapter and a 6" extension. I used Seafoam Deep Creep and the sensor popped out without much effort.
I didn't have to remove or disconnect anything other than the sensor connector.

The old sensor was covered in black soot.
The codes haven't come back and car's been running very nicely. I will keep an eye on the fuel mileage for any improvement.