2001 Volkswagon New Beetle mystery plug.

From the location and connector appearance, it's possibly an O2 sensor lead, see below link:

Can you give the wire colors?

It looks like a heated O2 sensor connection.

Hi Steve,

Looking at what Heron linked to here,

Thanks for your reply.

I think you'll find that there are 2 white wires, a gray wire and a black wire. Follow the wire bundle, it should go to the O2 sensor. It appears that that leasd isn't connected to an ECU lead as it should.

Is the check engine light staying on? Does the light work? If it's an O2 sensor lead, there should be a code stored, and if the light is working, it should be on.

I won't be able to have another look at the car until next week but please let me know if I've understood you correctly. The wires in the photo go to the O2 sensor. Then the orphaned, hanging connector plugs into another cable, that has yet to be located, which then goes to the ECU. Is that right?

Thanks for your reply.

Put the following into google/images and look at the pics:

It would certainly seem so and should be relatively easy to verify.

As it appears to be an OEM (and not a universal aftermarket replacement) type lead, its mating plug or receptacle, if still present and intact, should be readily locatable within an inch or three of that correctly routed harness.

You're welcome. I wish you success. Good luck.

"David Farber" wrote in news:jsq546$8jq$ snipped-for-privacy@dont-email.me:

Is the Check Engine light on?

That looks like the vehicle side of the connector. The part that plugs into it is going to be attached to the O2 sensor which should be in the exhaust system. Should be two of them, one in front of the converter and one behind.

As earlier alluded, it looks like the post (rear) cat (converter) sensor lead to me. An inspection following the wiring should provide a quick and easy determination These pix may prove to be of interest and/or assistance:

From what I know about the history of the car, soon after the car was purchased used, several months ago, the light did come on. Then, the seller did something to fix it, and then the light did not come on after that. That was going to be my other question though. How can the sensor be disconnected on not trigger the light to come on?

Thanks for your reply.

Hi Heron,

Those two images pretty much explained everything. (-:

Thanks for your reply.

"David Farber" wrote in news:jsr150$vo4$ snipped-for-privacy@dont-email.me:

Does the Check Engine light EVER illuminate, even during that time when you're starting the car and all the other idiot-lights come on?

If the Check Engine light NEVER comes on at ANY time, EVER, then somebody has removed the bulb. And that's only ever done to hide a problem...

If what they did was to take the light bulb out....

--scott

"David Farber" wrote in news:jsr1gc$1ee$ snipped-for-privacy@dont-email.me:

As I sais yesterday, check to see if the Check Engine light EVER comes on at ANY time, EVER.

If it does NOT, EVER, then the bulb has been removed to mask a problem.

If it's the downstream oxygen sensor that's been unplugged, the ECM is probably setting a P0420 trouble code, which usually means replacing the cat.

Or it has failed, or it's shrouded, or it's otherwise disconnected.

To cut to the chase, if you aren't subject to the costs incurred for repairs from failing an emissions inspection, and are not experiencing driveability issues (possibly resulting from a clogged converter), know that you need not necessarily do anything at all.

"Heron" wrote in news:jssg2v$g63$ snipped-for-privacy@speranza.aioe.org:

True, but the determination rests with what, specifically, is being detected by the ECM. It will be reporting the disconnected oxygen sensor, but that sensor was disconnected for a reason. The DTC(s) will tell the tale.

And a below-threshold catalytic converter is unlikely to be plugged, but much more likely to have simply lost some of its oxygen-storage capacity.

I believe it does come on when you turn the key to "on," before your start the car. I'll check again when I see the car in a few days.

Thanks for your reply.