Which oxygen sensor for P1117 code?

[SeaSlug]

Hello,

I am looking for some help in working out which of the after cat oxygen sensors I should be concerned with for the P1117 ODBII code. This is the only code I am getting back for the check engine light so I guess the culprit is this partuculoar sensor and not something further upstream. The code text in the excellent code list on this site says that it is sensor 1 but is that the sensor that is in the left hand catalytic converter or the one in the converter to the right when looking from the rear of the car? Additionally, does anybody have any advice or tips for replacing these sensors? I am assuming that I can just replace the bad one. and not both as I only ordered one of them.

Many thanks,

Chris

2001 Lapis Blue/Gray 996 Coupe.

[1999Porsche911]

P1117 is for the left bank exhaust, which is the driver's side. There are 2 sensors on each side of the car, but they are not for the same bank on the engine. The after cat sensor you are looking for is actually located on the right side of the exhaust since the exhaust exits on the opposite side of the car. The sensor is on the pipe right before it enters the right side muffler. I forgot what size wrench, but the sensor can easily be removed with an open end wrench.

Let the engine cool and disconnect the sensor connector and unscrew the sensor from the pipe. Install the new one and reconnect.

Edited March 28, 2005 by 1999Porsche911

[Loren]

22 mm wrench.

[SeaSlug]

Many thanks for the help.

[SeaSlug]

I got under my car and I do not have any sensors just before the pipe enters the muffler. The only ones I have are one upstream of the catalytic convert and a second in the side of each of the catalytic converter itself.

Is the one screwed into the side of the catalytic converter the one I should be concerened with here?

[1999Porsche911]

No...the other one on the pipe that goes into the passenger side muffler.

[SeaSlug]

Thanks for your help so far but I am still not finding what you describe.

Did something change for 2001 model year from what you are describing? I do not have a sensor near the muffler.

As I follow the exhaust system it has a three into one manifold from the engine. Then there is a joint to the rest of the exhaust pipe running left to right across the back of the car. About three inches further along there is the before cat sensor. Then after another few inches is the bulge which is the catalytic converter. This bulge has a sensor coming out of it about half way along. Then after the catalytic converter the pipe drops back to normal diameter, continues across the car from left to right and then enters the muffler on the passenger side. There are no sensors between the catalytic converter or the muffler, nor is there any in the muffler itself so the after cat oxygen sensor must be the one sticking out of the catalytic converter itself.

I am not the original owner of the car but I have no reason to think that the exhaust is not the stock piece.

[1999Porsche911]

Thanks for your help so far but I am still not finding what you describe.

Did something change for 2001 model year from what you are describing? I do not have a sensor near the muffler.

As I follow the exhaust system it has a three into one manifold from the engine. Then there is a joint to the rest of the exhaust pipe running left to right across the back of the car. About three inches further along there is the before cat sensor. Then after another few inches is the bulge which is the catalytic converter. This bulge has a sensor coming out of it about half way along. Then after the catalytic converter the pipe drops back to normal diameter, continues across the car from left to right and then enters the muffler on the passenger side. There are no sensors between the catalytic converter or the muffler, nor is there any in the muffler itself so the after cat oxygen sensor must be the one sticking out of the catalytic converter itself.

I am not the original owner of the car but I have no reason to think that the exhaust is not the stock piece.

<{POST_SNAPBACK}>

Sorry I confused you. In your example above, the first sensor you come upon when starting folloing the pipes from the headers (3 pipes joining to one), is the BEFORE cat sensor. The next one following the same pipe is the AFTER cat sensors. This is athe sensor closest to the muffler. This is the sensor in question.

This is true for all cars.

[SeaSlug]

Many thanks for your help with this. I got the sensor changed this weekend and it is working out great.

All the best,

Chris.