O2 sensor connectors

So It looks like I will need to replace my O'2 sensors.

2000 Base 2.7.

I first got a code 5 years ago. cleared and watched. 3 years later - same.
This year, about 2 months ago, I did the same thing again. But the code came on last week.

So either the sensor is getting worse, and more quickly, or there is some other intermittent issue.
Either way, it is the same code 4 times in a row. So it is time to further diagnose. And with close to 80K on the odo, they are probably due soon anyway.

So, where to purchase?

Pedro - is there a source that helps you?

Others - is there a known discount code or good deal?

The usual suspects are close enough in price, it comes down to preference.

ON BTW - on the 2000, there are differences between front and back. I have seen it reported that the 4 sensors are the same., but two suppliers confirmed that is NOT the case. YMMV, but I will likely order 2 of each set. If they are the same, then no harm. If they are different - problem saved.

The sensors are the same, the difference is the length of the wiring (front-to-back).
Most of the time the issue is not the sensor.
When you get a code, specific to a particular, such as O2 sensors, what the code is telling you is that the readings from the O2 sensor are out of spec.
It could be that the sensor is bad, but more likely something upstream of the sensor is making it read out of spec.
An air leak (vacuum) can do that, as well as a bad secondary air pump, fuel pump, fuel pressure regulator, etc., etc.
The fact that your sensors are nearing 80K doesn't mean anything. Mine are nearing 300K on the original sensors.
Happy Boxstering,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

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Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

Is it in the rear trunk by chance?

Scanning posts here and on other boards, an intermittent P1117 was triggered by a loose wire at the computer.
On the day I threw the code, I had several full brief cases in the trunk. Plausibly, the load could have shifted and bumped the connection - thus throwing the code???

I appreciate I am speculating as I go, but it could explain why the code is intermittent and not an issue over years at a time.

As a bonus, the fix is free.

If not in the trunk, where do the o2 sensors attach?

The sensors connect to the main wiring harness under the car.
The DME is in the rear trunk, behind the trunk liner on the left (driver) side of the trunk.
It's rare that a briefcase would affect the connectors, but it's worth a look-see.
Happy Boxstering,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

As Pedro said, they both clip onto connectors that are on the main wiring harness.

The front one is clipped onto a diagonal frame member under the car where the engine and transmission meet.

The rear one is in the fender area outside of and under the rear trunk, basically straight up from the sensor.



Edited 1 time(s). Last edit at 08/29/2019 05:38PM by Boxsterra. (view changes)

"loose wire at the computer"?

The DME connector is one single plug that has 88 pins. Those go to wires in the harness that have electrical connectors on them. It's highly unlikely there is a "loose wire at the computer." It is entirely possible there is a loose wire in the O2 sensor plug or that the wire to the O2 sensor got yanked/crushed/melted at some point.

P1117 is for bank 1 after the cat, i.e. passenger side rear. Check the electrical plug for that. Make sure it's seated properly. Make sure the pins are all intact. Follow the wires to the O2 sensor and look for anomalies.

If you don't see anything you can try swapping the sensors to see if the problem is the sensor.

Edit: Just looked at the diagram and the O2 sensors go through the X59 plug (white plug to the left of the DME).

Wiring for Bank 1 O2 sensors are are:
DME pin 77 → X59 plug pin 17 → O2 plug pin 4
DME pin 1 → X59 plug pin 15 → O2 plug pin 2



Edited 2 time(s). Last edit at 08/29/2019 05:50PM by Boxsterra. (view changes)

My post was speculation based upon a post in another forum.

That poster bought o2 sensors. It did not correct the problem. After longish diagnostics, the issue was traced to the connection at the ECU.

Superimposed on that was the use of the trunk when the light illuminated. I was driving from Hartford to Stamford on the Merritt parkway near BPT. The rear trunk contained two briefcases from the Court appearance that day. It is likely that the top most case moved around a bit in transit. It is also likely that the movement would have impacted the ECU.

Couple those known facts with the further fact that the code seems to be thrown once every 2 or 3 years, one might think an impact in the trunk could be a culprit.
Checking is simple and free. If the loom is fully seated and snug, we go back to the original plan.

There is no chance that briefcases in the trunk would knock a DME wire loose.

You can check the seating of the DME plug. Pin 1 ("oxygen sensor heating behind catalytic converter") is the one nearest the latch so I suppose it's possible though that pin is shared with both after-cat O2 sensors so if you're getting only that one code that's probably not it.



Pin 77 is the signal wire.

... check connectors for corrosion...

a couple minute search indicates p1117 for porsche might be the heater portion of the sensor... that one might be thicker gauge than the signal wire... but more also point to a coolant temp sensor...

I have no 1st hand experience with this problem, but being intermittent suggests wiring,

... it's not a lean code?

good luck, let us know how it goes...



Edited 1 time(s). Last edit at 09/03/2019 09:31AM by Petee_C. (view changes)

The car has a set of conditions that trigger this code. That set of conditions may only be occasionally met. If the O2 sensor heating element sometimes goes out of spec it won't always trigger the DTC.

It's also worth noting that if you have any of several other codes, this code can be ignored until those are resolved.

If you don't want to replace the sensor, why don't you swap them left/right and see if the code changes from P1117 (bank 1) → P1121 (bank 2) as some crazy person recommended 5 years ago?

There is only one code.

It has appeared four times in five years. Twice it went away with me doing nothing. Twice I cleared the code. I did not swap the sensor because of the long intermittent nature. The time delay between CEL's makes the swap test less than effective.
Further, i was of the opinion that swapping 16 (ish) year old parts might just as easily insert problems into the analysis. The test would be imperfect due to the introduction of new variables.

In each occasion the CEL was triggered, I believed watchful waiting was the preferred course. If the car runs fine and passes inspections, why change parts. If the CEL becomes regular, it would be easier to diagnose.

Swapping the parts is easy and not likely to introduce any issues unless you use a hammer (Porsche persuasion tool) to remove them. The fact that it is intermittent suggests that you should swap them and forget about it. When the code recurs, it will tell you the next step (which I predict is "replace the sensor" but only time will tell). Other than (potentially needlessly) replacing it, how else are you ever going to diagnose it?