P2096 Porsche fault code 16 - Oxygen sensor ageing Delay bank 1

[Silver_TT]

Here's the latest update if anyone can help:

The o2 sensors came today. I had first ordered from AutohausAZ for $128 a sensor but was really annoyed that I ordered them on a Friday afternoon and the following Tuesday evening they still hadn't shipped. So, believe it or not, I actually ended up getting these on Amazon for under $100 each (found an old Logray post where he said to check Amazon). Anyway, they arrived today and are legit. In the retail Bosch box to boot. Under $400 for all 4 shipped.

Precat: http://www.amazon.com/gp/product/B000VASQ2I/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1

Postcat: http://www.amazon.com/gp/product/B000VAZK8Q/ref=oh_details_o01_s01_i00?ie=UTF8&psc=1

Anyway, so here's where my trouble starts (and correct me if I mix up the sensors or make other mistakes). I'm only doing the drivers side right now, and the only part(s) I've removed is the ram air duct. How am I supposed to get the sensors off? I'm using the tools in the picture attached. Is there something better I should be using? The precat sensor is much easier to get to and I can get my o2 sensor wrench around it...but there's just not enough room to attach my wrench into the socket and turn. The angle is awkward. The postcat sensor is REALLY tough to get at. It's really up in there -- on top of the catalytic converter drum -- and the engine is so crammed together there's just not a lot of gaps to get your tools up there. I wanted to be able to get at it from the top (engine compartment) because it's real close, but there's not enough room to get my hands in there. Assuming I'm supposed to get at both of these from the bottom of the car, I just don't see any openings where I can get the wrench in there at the right angle and turn. Even if I was able to somehow get the postcat sensor off, I don't know how I can get my hands in there to get the new sensor seated and screwed in before I would even think about tightening it up.

Advice on how to actually get these out from anyone that's done this would be greatly appreciated. Conceptually it's so simple and I can see everything. I just can't get my tools in there.

Edited December 29, 2023 by Silver_TT

[Ahsai]

Bentley manual says remove the sensors from the bottom of the car. Have you tried from the bottom?

Edited March 2, 2013 by Ahsai

[Silver_TT]

Yes, I am trying to get to them from underneath the car. Unless there are some other tools that would make this easier, I just don't see how to get my tools up there with the o2 wrench on it. Especially with the post-cat sensor that's on top of the catalytic converter drum. The pre-cat is much more accessible and I could probably figure that out eventually...although I was still having trouble with that too. I'm also doing this with the car jacked up -- no lift.

[Ahsai]

Looks like some folks faced the same problem and had to remove the cats but at least one managed to remove the sensors with a regular wrench without removing the cats. Check post #12 here http://forums.rennlist.com/rennforums/996-forum/514234-o2-sensor-removal.html

Will this tool help? http://www.tooltopia.com/calvan-tools-843.aspx?utm_source=pricegrabber&utm_medium=cse&utm_term=CAL843&utm_campaign=pricegrabber_r1

Hope JFP or someone else can chime in. Also don't forget to hit the sensor and any bolt you need to loosen with PB blaster or Kroil before removal.

Edited March 2, 2013 by Ahsai

[JFP in PA]

Take a look from the top down after removing the intake air tube, if you are using the sensor wrench I like, you should be able to get 3/8 drive extensions down to it (place sensor wrench on the sensor from below, then work from above), perhaps with a "wobble" joint in the middle depending upon the length of your extensions.

[Silver_TT]

I got them out this morning just now. I recommend removing the entire air filter housing no matter which side you are doing (you need to do it for the passenger side for sure). After this is out you can get to the 2 sensors on top of the cats from the top (engine compartment) but I strongly recommend using an open-faced wrench. There just wasn't enough room to get the tools I show above in there (at least for me, I'm sure the pros are much better).

Anyway, it looks like my cats are bad (especially Bank 1). See attached.

Questions from here:

1. What should I do? Bank 1 readings, if I understand correctly look BAD. Bank 2 looks like it's half working.

2. Assuming I need new cats, I guess it's not worth asking Porsche since I understand the warranty is 8yrs/80K miles and I have a 2002 with 102K miles. Would you guys recommend going again for the OEM cats or someone like Fabspeed? Or someone else?

3. Should I be looking at anything further upstream that could be cause for concern?

4. How much are my old/broken cats worth at a junk yard?

The strange thing is, you wouldn't know there's a problem with the car driving it. Seemingly no loss of power or anything else that might be alarming. I have read some other posts though that said there might have been a problem with the 2002's cats, etc. I have seen other posts with similar issues. Take a look at some of these if you are interested:

http://www.6speedonline.com/forums/996/163011-what-does-dead-catalytic-converter-looks-like.html

http://forums.rennlist.com/rennforums/996-forum/572427-wtb-cats-for-a-2002-996-a.html

http://forums.rennlist.com/rennforums/996-forum/724702-what-to-do-when-the-fault-codes-reads-catalytic-converter.html

http://forums.rennlist.com/rennforums/996-forum/699181-catalytic-converter-lemons-to-lemon-aid.html

Edited March 3, 2013 by ferrugia

[JFP in PA]

I got them out this morning just now. I recommend removing the entire air filter housing no matter which side you are doing (you need to do it for the passenger side for sure). After this is out you can get to the 2 sensors on top of the cats from the top (engine compartment) but I strongly recommend using an open-faced wrench. There just wasn't enough room to get the tools I show above in there (at least for me, I'm sure the pros are much better).

Anyway, it looks like my cats are bad (especially Bank 1). See attached.

Questions from here:

1. What should I do? Bank 1 readings, if I understand correctly look BAD. Bank 2 looks like it's half working.

2. Assuming I need new cats, I guess it's not worth asking Porsche since I understand the warranty is 8yrs/80K miles and I have a 2002 with 102K miles. Would you guys recommend going again for the OEM cats or someone like Fabspeed? Or someone else?

3. Should I be looking at anything further upstream that could be cause for concern?

4. How much are my old/broken cats worth at a junk yard?

The strange thing is, you wouldn't know there's a problem with the car driving it. Seemingly no loss of power or anything else that might be alarming. I have read some other posts though that said there might have been a problem with the 2002's cats, etc. I have seen other posts with similar issues. Take a look at some of these is you are interested:

http://www.6speedonline.com/forums/996/163011-what-does-dead-catalytic-converter-looks-like.html

http://forums.rennlist.com/rennforums/996-forum/572427-wtb-cats-for-a-2002-996-a.html

http://forums.rennlist.com/rennforums/996-forum/724702-what-to-do-when-the-fault-codes-reads-catalytic-converter.html

http://forums.rennlist.com/rennforums/996-forum/699181-catalytic-converter-lemons-to-lemon-aid.html

Yeah, bank 1 is not looking good, and bank 2 does not look far behind.

Porsche will not be of any help as you are way past the warranty points. But it never hurts to ask, you may catch them on a good day………

Cats die from vibration, age, and mileage unless fouled out by something like engine oil. I doubt anything upstream is an issue.

You may be shocked to find that most dealers now impose a "core charge" for old cats, not unlike alternators or starters. Even dead, the rare metal inside the cat is recoverable and quite valuable.

[Ahsai]

What JFP said. Also, it's not strang because your front sensors are working correctly, there's no performance difference. The only diff is you are emitting less clean combusted gas.

[JFP in PA]

I'm sure the pros are much better.

Perhaps; but as Warren Buffet once commented, “It is real easy to look like you can walk on water when you know where all the rocks are; but it takes years of getting wet to find them all.”

Quite often, when working in very confined spaces like this project, something as dumb as the position you hold your hand in while inserting it in there makes all the difference in the world.

[Silver_TT]

What JFP said. Also, it's not strang because your front sensors are working correctly, there's no performance difference. The only diff is you are emitting less clean combusted gas.

That's true. I guess I just meant I find it strange I have no symptoms. If the cats were clogged (oil, etc) then I would expect to get low pressure through those cats. If the honeycomb inside the cat was broken from vibration, I understand that you can hear it in there when you tap on the cat with a rubber mallet. I don't get either of these symptons. Maybe it's just possible that the precious metals in the cats have just reached their lives in terms of their ability to catalyze at 100K miles. However, this doesn't seem to trigger the CEL very aggressively as I've only gotten the P0420 and P0430 one time (both at once), despite the fact that you can see there's an issue with the post-cat voltages, and I drive the car every day.

So I'm having my racing tires put on this week. I ordered a 20oz bottle of Techron from Advanced Auto Parts yesterday for $6 (they are running an online special). One day after work this week after traffic dies down I will add the entire 20oz bottle of Techron and then fill up the tank with gas. Then I will get on the highway and run the hell out of the car for an hour to try to burn up anything in the cats. If that still doesn't solve the problem I will be ordering new OEM cats at the end of this week. If that's the case I will make a few phone calls but if anyone knows of pricing cheaper than Suncoast's $1594 per cat, please let me know. If I end up doing the cats I may be looking for some guidance how to get those on. It looks pretty simple--really simple if the mufflers don't need to come off the car.

I'll let you guys know what happens. Thanks a lot for the input. The aggregate knowledge of the people on this site is outstanding; it really is amazing. I very much appreciate it.

Edited March 4, 2013 by ferrugia

[JFP in PA]

Internally, the main cat is a high surface area honey comb structure (the cat’s efficiency is dependent upon the available surface to react with the gas stream):

Cats cease to function properly when the surface of the honeycomb becomes coated with crud that prevents the gas stream from coming in contact with the honeycomb, but at the same time does not totally block exhaust flow through the honeycomb passages. When the honeycomb becomes even partially blocked, then the performance of the car suffers due to increased back pressure not allowing the cylinders to fully exhaust the spent gases. If mechanically blocked enough, the car won’t even start.

[Ahsai]

Sounds like a great plan cause you have nothing to lose anyway by trying the techron treatment. Seems your cats are marginal and that's why the CEL is only tripped from time to time due to the two-trip triggering logic. I think at this point, u can even wait till you have solid CEL before changing them out. Btw, driving on the tracks do shorten the cats life but I think that's the price to pay. I think a lot of racers have changed theirs to sport cats (lower cost and lower back pressure).

[Silver_TT]

I don't mean to belabor this thread but I got the CEL again last night so if the Techron and a long hard drive doesn't fix the problem later this week I want to move forward and get this fixed.

I just talked to the local dealer and obviously they agree that the cats could be suspect... he also recommended Techron (and a similar one made my Lucas). He said before replacing the cats they would first look for a potential vacuum leak. Any thoughts on this? I'm basically wanting to narrow this down to be absolutely sure it's the cats before I spend $3,200+ in parts on the cats (in addition to the $400 in oxygen sensors). I would hate to drop $3,600 and then find that it is something else.

Edited March 4, 2013 by ferrugia

[Ahsai]

Or you can pay the dealer one hr labor ($120?) to diagnose it to get an "absolute" peace of mind. Could also ask them to check if there's anything underlying that kill the cats so you won't have your new cats fail again the same way. However, the cats could have failed naturally due to age and mileage.

Edited March 4, 2013 by Ahsai

[JFP in PA]

I don't mean to belabor this thread but I got the CEL again last night so if the Techron and a long hard drive doesn't fix the problem later this week I want to move forward and get this fixed.

I just talked to the local dealer and obviously they agree that the cats could be suspect... he also recommended Techron (and a similar one made my Lucas). He said before replacing the cats they would first look for a potential vacuum leak. Any thoughts on this? I'm basically wanting to narrow this down to be absolutely sure it's the cats before I spend $3,200+ in parts on the cats (in addition to the $400 in oxygen sensors). I would hate to drop $3,600 and then find that it is something else.

I completely appreciate your concerns.

Vacuum leaks of any significance typically cause other problems, and quite often throw unique codes on their own; you have not mentioned seeing any of those, so I would not hold much hope it is a vacuum leak.

Go back to my suggestions concerning getting the car tested using an emissions sniffer; if one or both of the cats are toast, the car would have very high emissions levels, and that could not result from any other source.

[Silver_TT]

JFP -

You know, I actually tried to get the sniffer test done. I called all around. I could only find one shop that has a device called a Sun 450 but they said it's no longer working and hasn't been for a few years. Seems that now that everyone uses the OBD to read the codes for emissions, no one has this machine any longer. They also used to have state testing stations around here but when I called they said the state has shut them all down (to save costs I assume) and this is all being done at authorized affiliate testing stations (ie. gas stations with a OBD reader).

Edited March 4, 2013 by ferrugia

[JFP in PA]

Try looking for a dyno shop; they sometimes use them while setting a car up on the rollers. Another possible is a shop that works on the late 60’s “muscle cars”, the only way to tune them is with a sniffer as they did not have O2 sensors.

Most of the world has moved to dependency on EPA mandated “advanced emissions testing”, which is totally OBD II.

[Silver_TT]

Seems like these "sniffers" are impossible to find these days -- at least around my neck of the woods. One of the best wrenches around here (who I like very much but don't always go to because he's 50 miles away) has a dyno at his shop and he said just now that he's been looking around for one of these machines (for the exact reason JFP stated) for a while but hasn't been able to get his hands on one.

If the Techron doesn't fix it I think I'm going to bite the bullet and replace the cats. No wonder Porsche is the most profitable car maker in the world.

[JFP in PA]

A thought; state emissions standards vary widely, but many urban areas still require special emissions testing for certain vehicles, like class three and above trucks. Our 2012 shop truck, with full cats and four O2 sensors, has to pass what is called a "two speed idle test", which is run on a dyno at two different low RPM runs with a sniffer in the tail pipe; it cannot pass on just the I/M Readiness test off the OBD II port. To get it certified, we do the safety stuff (brakes, tries, etc.) and then it goes to a nearby shop for the run on the rollers to get the last sticker.

You may want to check your state emissions requirements (most have detailed on line resources) and see if something similar is required in your area. Because "a sniffer is just a sniffer", if they do require special testing on heavier trucks, you have just found your testing source.............

[Silver_TT]

JFP, you have an answer for everything! But they don't want to make this one easy on me. The "two speed idle test" using a "sniffer" was discontinued in Feb of 2012 here and all tests are now being done using the OBD II. Looks like I'll be taking Ahsai's suggestion and paying the dealer an hour labor to diagnose just to be sure. I'm almost sure it's the cats given all the stuff we've been though.... but I want to be sure before I drop this kind of money.

[JFP in PA]

JFP, you have an answer for everything!

No, I'm just thick skulled and don't like to give up easily. I've always held that there has to be another way to do almost anything......................" Subitum, et superatus"

[Y2K911]

Superb thread! Highly informative on the O2 and Cats end of things, and let's hope ferrugia conquers against all odds as JFP concludes above.

With 142k kms, I'll be in the same position in the not-so-distant future so it is very much appreciated!

Martin

[Silver_TT]

Glad to contribute the information and hope it can help inform people or help someone with a similar problem in the future. The biggest issue I see when searching these threads is that people often aren't very detailed and even more often don't post the conclusion. I would find threads from years ago where people had what appeared to be the same problem but then they would never follow-up and say if they fixed it or how they fixed it. Not really that helpful.

At any rate, I ran a 20oz bottle of Techron through hoping to burn out any residue in the cats (possibly from running rich on account of a bad o2 sensor before I replaced them) and it did't have any effect on the post-cat voltage readings. So I'm having the cats replaced next Friday. Will report back on how that turns out.

[Silver_TT]

Back to the o2 sensors, I took some images during replacement of the o2 sensors. The two images below are of the engine compartment on both drivers side (left) and passenger side (right). All that I have taken out is 1. the air duct (it snaps right off, two clips on the sides and one on the bottom) and 2. the filter housing box (also very easy, just a few screws and pulls out). As mentioned earlier, I used a open-faced wrench (22mm) because it is "thin" and there's not a lot of room to work.

The two pre-cats can be accessed from the bottom of the car. The post-cats are on top of the cat's drum and can be accessed from the top, as shown in the pictures below. I have circled the location of the sensors in red, and placed arrows indicating where the wires lead to and where you can get your hands in with a wrench. Those red clips on top of where the sensors plug into the DME/ECU can be popped up with a screwdriver.

Edited March 9, 2013 by ferrugia

[Silver_TT]

Problem was solved by replacing the cats. Now the post-cat sensors don't follow the pre-cat sensors at all. They stay very close to .7 V constantly on both banks, which means the cat is doing its job well.

After I got the cats off I could shake them and hear the honeycomb broken inside. I guess when I was tapping them with a rubber mallet when they were still attached on the car, I must not have been hitting them hard enough because I couldn't hear it then. At any rate, if I had to guess I would say this must have been from vibration/age. The good news though is that the insides of the cats looked good so there is certainly nothing wrong with the car upstream. So the car is 100% back in working order, running like a champ.