02 sensor
 

I replaced my 02 sensor 4 months ago 1700 miles. Everything went well the CEL went out after a day. So back to normal until a couple of days ago. My CEL came on again. I connected my scan tool and this is the reading I got. "P0140 $11, 02 Sensor circuit no activity detected Bank 1 Sensor 2". Does this mean the sensor has stopped working.
By the way I don't know what make the sensor is I bought.

Is it the same sensor you replaced? Did the new sensor come with a Porsche connector, or did you have to splice the old connector on?

Could be bad if it was low quality (stick with Bosch). It could also be a faulty connection. I'd start with pulling the connector, visually inspecting the pins (clean with contact cleaner), then reconnecting (make sure the cam lock is fully seated).
Also check the wiring to make sure it isn't rubbing anywhere or loose enough to touch the exhaust.

+1

Assuming you bought OEM equivalent sensor so no funny business with the part,
What was your prior code? You have 4 sensors.....the two rear ones won't generate a code IIRC.

If its the same code as before, get under the car and reseat the O2 connector.

02 sensor
 

The prior code when my original sensor put the CEL on was something like "sensor not responding quickly enough"
My car has 2 sensors 1 on each side (UK)
Same code different comments.

Thanks for your response.

02 sensor
 

It is the same sensor, yes and it came with the Porsche connector.
I have had a look for chafing, everything seams ok. I haven't disconnected it yet which I will do. I did make sure when I fitted it that it was locked properly.

Thanks for your response.

The old sensor should have had a Bosch part number on it in addition to a Porsche part number. If original.

The replacement part was what brand?

02 sensor
 

I don't think it was a branded part. This is the ebay number in the UK 121740208974
I emailed them 4 times, I finally got a reply today, they say they only do a 3 months warranty so I am out of warranty by a month. I am going to press them on this as I can't see anywhere on their ebay ad that says anything about the warranty.

When you eventually buy all new sensors, make sure the prt number is correct by asking here. Some of the Interchange manuals are incorrect. Yes, only use Bosch in my experience and replace all of them. They are cheap.

Bosch makes the parts for Porsche. Porsche puts a part number on them and provides a box and extra mark up. The Bosch part is the same provided as the Porsche you get the right part. There is a cross reference at the bottom of this page.

02 sensor
 

Thanks for the info.

02 sensor
 

I have ordered the Bosch part now, thanks.