weird plug (updated). Please read

rnln · 02-20-2006, 03:03 PM

I posted earlier about the weird plug in the trunk and someone sugested it is the Os sensor plug.
I got down there and found that it is not, or at least it's not the direct plug from the O2 sensor.

Below are some pics of the related component.
1- is that weird plug with 1 female and 2 males prongs.
4- the aluminum spuare part is where that cable/plug comming from.
2- I saw there is a black thing (please look at the expanded pic) with many female prongs on it and there is nothing plug to it at all)
3- is the O2 sensor cable/plug; which is pluged into another similar looking cable leading toward the firewall and stay tight in there. I try to pull but it's stuck in there.
PS: my car is running normal, although the RPM is not stable most of the time, especially when just started. It is jumpnig up and down around 800-900 RPM.
Any idea what it is? Should it plug to somewhere?
Thanks.

Por_sha911 · Por_sha911's Garage

Looks to me exactly like the plug for my O2 sensor. It may be that someone used an old O2 plug to setup some other type of connection.

ischmitz · ischmitz's Garage

3. is a relay socket for an option that you do not have. Maybe a rear wiper or something similar.....

Not sure about (1) but it sure looks like the O2 sensor plug. I am surprised that Porsche would have put two of the same plugs into the same area. That is very un-Porsche. Have you checked whether it goes into the main harness. Maybe it's a dummy lead that the previous owner put in to ground the O2 sensor input to run without O2 sensor. Something to fool the smog station.

Cheers,
Ingo

Hugh R · 02-20-2006, 03:44 PM

Is it the plug that goes in the firewall on the left behind Item 1 which powers the tail lights?

rnln · 02-20-2006, 03:58 PM

ischmitz,
I know what you mean now. I will check. Another question though, where is the location of the main harness? And where the O2 sensor should connect to? To the main board ECU?

Thanks ischmitz.

Hugh R,
item (1) goes to item (4) and do nothing.
item (3) is the O2 sensor cable. The arrow is right at the connection between the o2 sensor and lead to the firewall. I don't know what it connect to in there.

jpahemi · 02-20-2006, 04:53 PM

Item #2 and thrid pic down is used to disable the idle stabilizer to adjust the idle. You need to run a jumper between two of the sockets (labeled a,b,c) to disable the stabilizer.
j.p.

rnln · 02-21-2006, 02:01 AM

jpahemi,
Thanks for the info.
Which 2 sockets of the 3 A, B, C?
Thanks.

jpahemi · 02-21-2006, 02:27 PM

If you connect a voltmeter to terminal A & C and start the engine you can check to see if the O2 sensor control is working properly (voltage should change from 0-12 v)
To bypass the idle stabilization (for adjusting idle), you bridge terminals B & C and adjust the idle on the throttle body.
Finally to check if the WOT switch is working properly, you connect the voltmeter to terminal B and ground; I'm not sure if you'll see 0-5v or continuity.

j.p.