Oxygen Sensor - Location and Part #
 

2000 Boxster 2.7 liter engine with approximately 132,000 miles.

The check engine light illuminated yesterday. My Durametric downloaded two codes:

P1276
Porsche fault code 22 - Oxygen sensor ageing Delay bank 2 below limit value

P0133
Porsche fault code 15 - O2 sensor ageing ahead of cat. conv. cylinder (1-3) below limit value

From my research, I found that Bank #1 includes cylinder #1 and is on the passenger side in a U.S. vehicle.

Bank #2 is on the driver's side.

Here are my questions:

My understanding is that I need to replace two oxygen sensors:

1. The one before the cat on the passenger side.
2. I also need to replace one on the driver's side, but I cannot tell from the information which one. Should I replace the one before or after the cat?

The part number for the O2 sensor shown on my Durametric is 986.618.620.08. Noting comes up when I search on that part number. Please suggest a good replacement sensor part #.

Does the fact that I have to replace two sensors at the same time seem odd and suggest that there may be another problem?

Thanks in advance.

P0133- Aging of O2 sensor ahead of the three way cat on Bank 1
P1276 - Aging of O2 sensor ahead of three way cat on Bank 2

It is unusual for two forward sensors to age fail at the same time. I would clear the codes with the Durametric and see if they return before replacing anything.

Thanks

I have already cleared the codes and I will see whether they return.

I checked my records (I also have the records of the previous owner) and I have only had to replace one O2 sensor during the life of the car. That was for a P1117 code - the O2 sensor after the cat on the passenger/right side of the car in 2007. I suppose it's possible that the two that set fault codes are just reaching the end of their service life at the same time. However, that seems like a low probability event.

The only unusual event is that I have been driving the car back and forth to work more than I usually do because I am having a problem with the alternator on my other car. However, the Boxster is not a garage queen and I drive it year round.

While I bow to JFP's expertise, I offer this which includes theory of operation as well as part numbers. You do not need to buy a Porsche part, Bosch makes the part for Porsche and there is a cross reference in the link. You can do it yourself with a special tool or any muffler shop can do the swap.

Thanks Mike. Your cross reference is helpful.

I replaced one O2 sensor in my Boxster and one in another car. If I recall correctly, the only challenge I encountered with the Boxster was difficulty reaching the electrical connector while laying on my back with the car on ramps. I have access to a lift at the auto hobby shop on the Army base where I work. I think I may use the lift if I have to change any of the sensors. I cleared the codes as JFP suggested. I've driven about 12 miles and they haven't returned. I expect time will tell.

I had a CEL again. I read the code and it is showing Bank 2 Sensor 1 as aging. Based on the date of my first post in this thread, it looks like 5 months since the last CEL. I cleared the code again and I will see how long it takes to return.

According the article Mike Focke linked, it appears that 100,000 miles is the average life expectancy of an O2 sensor. The car has 133,000 miles on the odometer and I've driven 103,000 of those miles. Even if the previous owner changed the sensors (which was not documented in the pile of receipts he gave me) all but one of my sensors has seen 100,000 miles of use.

I don't like to replace parts for the sake of replacing parts, but if the code returns in a few weeks, it may be time to start shopping for an O2 sensor.

You can look at the response of your O2sensor signal with the graphing feature on your Durametric. Then you will know if the response time is slow or not.

Rather then trying to explain what to look for in the graph, I would suggest you go to youtube and look up "ScannerDanner." Then find his video on "Oxygen sensor slow response test". Then you will have a visual on what to look for in the test.
Yes I know youtube can be a joke but Paul Danner is very very good at what he does.

I had one of those aging CELs and bought a single Bosch part and had a muffler shop replace the sensor for about a half hour on a lift price. Most was waiting for a cool down so they could work on it.

Several months later, I decided to replace the matching one on the other side just because. I used another muffler shop, same experience. You don't need to do that. I did lots of things like that, think $1200 worth of tires 2 months before I sold it just because they were 5 years old.