O2 sensor problem

[sfarris]

Mates,

I have a 2000 Boxster S, with an aftermarket breather. At 30K plus miles, we had some maintenance done. The check engine light was coming on, they replaced an O2 sensor, and some plug wires that were leaking oil. Two weeks later, check engine light is back on, and showing a slow data problem in the other O2 sensor. Is anyone familiar with this problem? Before you ask, i had the service done at a reputable Porsche mechanic, not a dealer shop.

Thanks in advance.

[Loren]

In many cases the O2 sensor is identifying another problem and is not the problem itself.

You need to have the fault codes read at your local auto parts store and report back here all the fault codes.

There are over 1000 things that can turn on a CEL and only a few are O2 sensors - even then the fault code will tell you which one (of the 4 on your car).

[sfarris]

In many cases the O2 sensor is identifying another problem and is not the problem itself.

You need to have the fault codes read at your local auto parts store and report back here all the fault codes.

There are over 1000 things that can turn on a CEL and only a few are O2 sensors - even then the fault code will tell you which one (of the 4 on your car).

They replaced a left bank sensor. The light is back on, and last time it scanned P0133 and 0153. Thanks a ton for any help!

[Loren]

P0133 Signal Period for Oxygen Sensor Ageing, Bank 1 – Above/Below Limit

P0153 Signal Period for Oxygen Sensor Ageing, Bank 2 – Above/Below Limit

Potential causes:

– Oxygen sensor ahead of TWC

– Wiring (oxygen sensors exchanged)

[mikefocke]

I wonder about that breather

O2 sensors are trivial to replace and non-Porsche parts are available for lots less than Porsche would charge and are exactly the same part. Even if you don't want to do the work yourself, buy the non Porsche part and let an exhaust shop do it for a half hour labor charge. It will take them 15 minutes.

Do you know which sensor was already replaced? It seems odd that another failure would occur on a new sensor so soon. And they do tend to last more like 50-60k miles and not the 30k you are reporting. Which makes me worry there is something else wrong and causing the sensors to fail.

More info here