Can Someone Help Me Interpret My Durametric O2 / Cat Data Please?

[cfiiman]

Hey all,

 

So I'm trying to track down a 2 code CEL that my 04 has thrown, they are PO421 & P0431.  I know these are Cat codes but since it could also be something else (bad 02, etc) I decided to record some live data to look at.  I'm very new to Durametric and used it to capture the below values and exported it to an excel file.  It is about 2.5 minutes worth of data and I wasn't sure exactly what to select in Durametric so I tried to get what I thought was appropriate to diagnose what to replace.  The Values I selected were:

 

 

1.  Exhaust Temp Ahead & After CAT

2.  O2 Sensor Voltage Downstream Bank 1 & 2

3.  Status of Catalyst Bank 1 & 2

 

I may be putting too much emphasis on temps, but based on the inlet/outlet temps of the CAT, I'm wondering if that is showing me the answer?  At the beginning the inlet temp was lower but not by a ton, then midway through till the end the outlet temps were lower which I think is a sign the cat is not working correctly.  I think the O2 readings appear ok since they don't jump around to much and stay around the .5V figure with mainly .6-.7 being the most common in the data stream which is where downstream O2's should be correct?  I have no idea what the Status of Catalyst is and was hoping someone could clue me in.  I selected it b/c I "thought" it might be important but the value is solid throughout not sure if that is good or bad or what or if it even tells anything.

 

I'm trying to plan my course of action which I've game planned to a few different things depending on what the data tells me:

 

1.  Maybe the CATS can revived with a chemical cleaner (doubtful).  I know that these codes will throw if the cats operate at less than 95% efficiency, so maybe mine is only slightly below that and can be cleaned a bit, but the temperature data difference at the inlet vs outlet is making me think this might be a waste?

 

2.  New O2 sensors.  These aren't too expensive but I hate just throwing new parts at something without something to back it up.  From the data stream it didn't look like they were too out of wack but maybe I'm missing something, I've certianly replaced them in other cars when I was having CAT codes and that corrected the problem so...dunno.

 

3.  New CATS.  I've found some reasonably priced aftermarket OEM fit/finish replacements from a company but hate to get into that if any of the easier stuff might work.

 

4.  Go all ghetto and put an anti-fouler in the downstream O2's to get the light off (last resort).

 

The car runs great and getting around 18 mpg in mostly city/some hwy, so that seems normal.  Just need some advice for those of you that know Durametric and can help a member out by looking at the excel data file.  If I missed some important data that I needed to log please tell me and I'd be happy to go data log whatever you all think I need to, again I'm new to Durametric and there are so many options I was a little overwhelmed and went with my "gut" feeling.  Anyway thanks for any help, here is the exported data from Durametric:

 

2004_Cayenne_Durametric_Export

Edited June 9, 2015 by cfiiman

[JFP in PA]

Hey all,

 

So I'm trying to track down a 2 code CEL that my 04 has thrown, they are PO421 & P0431.  I know these are Cat codes but since it could also be something else (bad 02, etc) I decided to record some live data to look at.  I'm very new to Durametric and used it to capture the below values and exported it to an excel file.  It is about 2.5 minutes worth of data and I wasn't sure exactly what to select in Durametric so I tried to get what I thought was appropriate to diagnose what to replace.  The Values I selected were:

 

 

1.  Exhaust Temp Ahead & After CAT

2.  O2 Sensor Voltage Downstream Bank 1 & 2

3.  Status of Catalyst Bank 1 & 2

 

I may be putting too much emphasis on temps, but based on the inlet/outlet temps of the CAT, I'm wondering if that is showing me the answer?  At the beginning the inlet temp was lower but not by a ton, then midway through till the end the outlet temps were lower which I think is a sign the cat is not working correctly.  I think the O2 readings appear ok since they don't jump around to much and stay around the .5V figure with mainly .6-.7 being the most common in the data stream which is where downstream O2's should be correct?  I have no idea what the Status of Catalyst is and was hoping someone could clue me in.  I selected it b/c I "thought" it might be important but the value is solid throughout not sure if that is good or bad or what or if it even tells anything.

 

I'm trying to plan my course of action which I've game planned to a few different things depending on what the data tells me:

 

1.  Maybe the CATS can revived with a chemical cleaner (doubtful).  I know that these codes will throw if the cats operate at less than 95% efficiency, so maybe mine is only slightly below that and can be cleaned a bit, but the temperature data difference at the inlet vs outlet is making me think this might be a waste?

 

2.  New O2 sensors.  These aren't too expensive but I hate just throwing new parts at something without something to back it up.  From the data stream it didn't look like they were too out of wack but maybe I'm missing something, I've certianly replaced them in other cars when I was having CAT codes and that corrected the problem so...dunno.

 

3.  New CATS.  I've found some reasonably priced aftermarket OEM fit/finish replacements from a company but hate to get into that if any of the easier stuff might work.

 

4.  Go all ghetto and put an anti-fouler in the downstream O2's to get the light off (last resort).

 

The car runs great and getting around 18 mpg in mostly city/some hwy, so that seems normal.  Just need some advice for those of you that know Durametric and can help a member out by looking at the excel data file.  If I missed some important data that I needed to log please tell me and I'd be happy to go data log whatever you all think I need to, again I'm new to Durametric and there are so many options I was a little overwhelmed and went with my "gut" feeling.  Anyway thanks for any help, here is the exported data from Durametric:

 

2004_Cayenne_Durametric_Export

 

First of all, it is always helpful to provide the car's year and model in these inquiries.

 

Assuming it is a Cayenne:

 

P0421 Catalytic conversion, bank 1 – above limit value Possible cause of fault - Oxygen sensors in front of and behind catalytic converter are interchanged - Catalytic converter faulty .

 

P0431 Catalytic conversion, bank 2 – above limit value Possible cause of fault - Oxygen sensors in front of and behind catalytic converter are interchanged - Catalytic converter faulty.

 

A little light reading on the subject of O2 readings and state of the cats (from a Boxster diagnostics manual, but the technology is the same):

 

  

 

You need to go back to your Durametric system and pull up the graphical display of the before and after cat voltages to see if they are following each other; if they are, you need new cats.

[cfiiman]

 

Hey all,

 

So I'm trying to track down a 2 code CEL that my 04 has thrown, they are PO421 & P0431.  I know these are Cat codes but since it could also be something else (bad 02, etc) I decided to record some live data to look at.  I'm very new to Durametric and used it to capture the below values and exported it to an excel file.  It is about 2.5 minutes worth of data and I wasn't sure exactly what to select in Durametric so I tried to get what I thought was appropriate to diagnose what to replace.  The Values I selected were:

 

 

1.  Exhaust Temp Ahead & After CAT

2.  O2 Sensor Voltage Downstream Bank 1 & 2

3.  Status of Catalyst Bank 1 & 2

 

I may be putting too much emphasis on temps, but based on the inlet/outlet temps of the CAT, I'm wondering if that is showing me the answer?  At the beginning the inlet temp was lower but not by a ton, then midway through till the end the outlet temps were lower which I think is a sign the cat is not working correctly.  I think the O2 readings appear ok since they don't jump around to much and stay around the .5V figure with mainly .6-.7 being the most common in the data stream which is where downstream O2's should be correct?  I have no idea what the Status of Catalyst is and was hoping someone could clue me in.  I selected it b/c I "thought" it might be important but the value is solid throughout not sure if that is good or bad or what or if it even tells anything.

 

I'm trying to plan my course of action which I've game planned to a few different things depending on what the data tells me:

 

1.  Maybe the CATS can revived with a chemical cleaner (doubtful).  I know that these codes will throw if the cats operate at less than 95% efficiency, so maybe mine is only slightly below that and can be cleaned a bit, but the temperature data difference at the inlet vs outlet is making me think this might be a waste?

 

2.  New O2 sensors.  These aren't too expensive but I hate just throwing new parts at something without something to back it up.  From the data stream it didn't look like they were too out of wack but maybe I'm missing something, I've certianly replaced them in other cars when I was having CAT codes and that corrected the problem so...dunno.

 

3.  New CATS.  I've found some reasonably priced aftermarket OEM fit/finish replacements from a company but hate to get into that if any of the easier stuff might work.

 

4.  Go all ghetto and put an anti-fouler in the downstream O2's to get the light off (last resort).

 

The car runs great and getting around 18 mpg in mostly city/some hwy, so that seems normal.  Just need some advice for those of you that know Durametric and can help a member out by looking at the excel data file.  If I missed some important data that I needed to log please tell me and I'd be happy to go data log whatever you all think I need to, again I'm new to Durametric and there are so many options I was a little overwhelmed and went with my "gut" feeling.  Anyway thanks for any help, here is the exported data from Durametric:

 

2004_Cayenne_Durametric_Export

 

First of all, it is always helpful to provide the car's year and model in these inquiries.

 

Assuming it is a Cayenne:

 

P0421 Catalytic conversion, bank 1 – above limit value Possible cause of fault - Oxygen sensors in front of and behind catalytic converter are interchanged - Catalytic converter faulty .

 

P0431 Catalytic conversion, bank 2 – above limit value Possible cause of fault - Oxygen sensors in front of and behind catalytic converter are interchanged - Catalytic converter faulty.

 

A little light reading on the subject of O2 readings and state of the cats (from a Boxster diagnostics manual, but the technology is the same):

 

  

 

You need to go back to your Durametric system and pull up the graphical display of the before and after cat voltages to see if they are following each other; if they are, you need new cats.

 

 

Thanks for the info, sorry it is a 2004 Base model, it says that on the excel file but people might miss it.  The problem is I don't think Durametric can do the upstream O2's unless I'm missing something, I can't find that selection to include in the analysis graphing, do you know for sure it is there?

[JFP in PA]

 

 

Hey all,

 

So I'm trying to track down a 2 code CEL that my 04 has thrown, they are PO421 & P0431.  I know these are Cat codes but since it could also be something else (bad 02, etc) I decided to record some live data to look at.  I'm very new to Durametric and used it to capture the below values and exported it to an excel file.  It is about 2.5 minutes worth of data and I wasn't sure exactly what to select in Durametric so I tried to get what I thought was appropriate to diagnose what to replace.  The Values I selected were:

 

 

1.  Exhaust Temp Ahead & After CAT

2.  O2 Sensor Voltage Downstream Bank 1 & 2

3.  Status of Catalyst Bank 1 & 2

 

I may be putting too much emphasis on temps, but based on the inlet/outlet temps of the CAT, I'm wondering if that is showing me the answer?  At the beginning the inlet temp was lower but not by a ton, then midway through till the end the outlet temps were lower which I think is a sign the cat is not working correctly.  I think the O2 readings appear ok since they don't jump around to much and stay around the .5V figure with mainly .6-.7 being the most common in the data stream which is where downstream O2's should be correct?  I have no idea what the Status of Catalyst is and was hoping someone could clue me in.  I selected it b/c I "thought" it might be important but the value is solid throughout not sure if that is good or bad or what or if it even tells anything.

 

I'm trying to plan my course of action which I've game planned to a few different things depending on what the data tells me:

 

1.  Maybe the CATS can revived with a chemical cleaner (doubtful).  I know that these codes will throw if the cats operate at less than 95% efficiency, so maybe mine is only slightly below that and can be cleaned a bit, but the temperature data difference at the inlet vs outlet is making me think this might be a waste?

 

2.  New O2 sensors.  These aren't too expensive but I hate just throwing new parts at something without something to back it up.  From the data stream it didn't look like they were too out of wack but maybe I'm missing something, I've certianly replaced them in other cars when I was having CAT codes and that corrected the problem so...dunno.

 

3.  New CATS.  I've found some reasonably priced aftermarket OEM fit/finish replacements from a company but hate to get into that if any of the easier stuff might work.

 

4.  Go all ghetto and put an anti-fouler in the downstream O2's to get the light off (last resort).

 

The car runs great and getting around 18 mpg in mostly city/some hwy, so that seems normal.  Just need some advice for those of you that know Durametric and can help a member out by looking at the excel data file.  If I missed some important data that I needed to log please tell me and I'd be happy to go data log whatever you all think I need to, again I'm new to Durametric and there are so many options I was a little overwhelmed and went with my "gut" feeling.  Anyway thanks for any help, here is the exported data from Durametric:

 

2004_Cayenne_Durametric_Export

 

First of all, it is always helpful to provide the car's year and model in these inquiries.

 

Assuming it is a Cayenne:

 

P0421 Catalytic conversion, bank 1 – above limit value Possible cause of fault - Oxygen sensors in front of and behind catalytic converter are interchanged - Catalytic converter faulty .

 

P0431 Catalytic conversion, bank 2 – above limit value Possible cause of fault - Oxygen sensors in front of and behind catalytic converter are interchanged - Catalytic converter faulty.

 

A little light reading on the subject of O2 readings and state of the cats (from a Boxster diagnostics manual, but the technology is the same):

 

  

 

You need to go back to your Durametric system and pull up the graphical display of the before and after cat voltages to see if they are following each other; if they are, you need new cats.

 

 

Thanks for the info, sorry it is a 2004 Base model, it says that on the excel file but people might miss it.  The problem is I don't think Durametric can do the upstream O2's unless I'm missing something, I can't find that selection to include in the analysis graphing, do you know for sure it is there?

 

 

Positive, it should be in the actual values under the engine sections.  These curves were generated off a 996 with a bad cat on one side using the Durametric software:

 

[cfiiman]

Great, I'll hook it back up and see if I can find it and report back with a new file, thanks man!

[ma77hewsu11ivan]

Having a hard time finding the durametric designator for the sensors ahead of the cats. Found both o2 downstream sensors easily. Lots of lands, ohm, etc... Thanks, Matt


2009 Cayenne S

[ma77hewsu11ivan]

Great, I'll hook it back up and see if I can find it and report back with a new file, thanks man!

Any luck finding them?? Thank you.


2009 Cayenne S