Silver_TT

Thanks for the reply, I have read a bunch of your other posts in the past. I actually saw jpflip's posted list previously -- Good list!! Most of those probems seem minor and some of the little things I'm fammiliar with from the 996 (window regulators, oil pressure sender, etc, etc). Definitely will ask them to check those coolant hoses in the PPI. The X50 on a used car costs a small fraction of the original $18K but the problem is there aren't a ton of them out there and I'm picky. When I have found them there was something weird I didn't like about the car, interior, etc.

Thanks for the response. Ya, I know about X50, it's pretty awesome. And, ya, so cool -- there's a guy here on RennTech too who has 300K+ as well. I'm looking for something solid like the Mezger. As far as the coolant line connectors, is there an easy way to tell if I have the car on the rack? Do they check this during a PPI? If this just has the original glue, is the problem inevitable, only a matter of time? At what mileage does this problem usually manifest itself? The car I'm looking at is coming up on 60K miles. Are there any other "gotchas" I should be considering other than this coolant line?

I am considering the purchase of a 2002 996 TT. I initially wanted the x50 package but I found a car that has Revo SPS. I did a search and read this is an ECU flash update and can add quite a lot of power depending on the other components it's coupled with (exhaust, etc). Maybe a stupid question but is this approved by Porsche (or is there anything bad it could do to the car)? Can anyone tell me what this addition is worth $ and what kinds of things I should be looking at related to it? What kind of performance increase would I be seeing? What kind of questions would an educated buyer want to know about this? Thanks in advance. 3/16/13 CORRECTION: The title of this thread should say "REVO SPS"

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.

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.

kgoertz, thanks for taking the time to follow-up. All very good info for me and for future reference for others I think. The only other thing I would add about the person replacing the cats with OEM multiple times is that it makes me wonder if there was something else wrong with the car causing the cats to die. The originals on the car come with an 8yr/80K warranty, at least in my state. The dealer here told me they should be good for 100-150K miles on average as a rule of thumb.

just sent you a PM

Thanks for the reply and I'm always open to ideas, so I appreciate the response. I have actually read your post you're referring to previously. In my personal situation, for what it's worth, I don't care too much about the sound (I have PSE) and the ~15 extra HP. Not saying there's no merit to that, but in my case I just don't value either of those too much. One thing I've heard conflicting info on: Do you ever get CELs with the aftermarket cats (o2 sensor related, high flow cats, etc)? Are there any issues with emissions testing? I talked to Fabspeed and they swear no CELs and their X-pipe is just as good as OEM in every aspect. To be honest I personally really don't like the thought of going non-OEM.... but I also don't like the thought of $3200 on two cats either. I always think about the worst case and I can just see something happening later and Porsche telling me it's because I went non-OEM. I was also curious how much rigging had to be done to get those cats in to your 996. As I found out last weekend simply trying to get 4 O2 sensors replaced, there is not a lot of room back there in the exhaust. I have never worked on a car with everything packed so tight together -- it gave me a new found respect for the pros. Interesting that you say the stock cats are known to go if you stress them on a track day. I know I don't have a Mezger turbo but this is supposed to be a "racecar". It seems ridiculous if the OEM cats can't take a nice flogging in a weekend at the track.

Thanks for the response. Yes, I definitely did consider eBay but no one is selling the ones I need for an 02C4S and when I checked the completed items history I don't see any that have sold recently so I wasn't holding much hope in waiting. It's a good thought though, so I apprecaite your input.

Without a doubt. Thanks

Thanks for the response, Loren. Ya, I like the guys over at Oklahoma Imports and I have bought some small stuff from them before -- very straight shooters on those transactions. Your later point is also very well taken and understood -- however, if I could in fact pick these up for $500 for the pair it would be well worth the risk vis-a-vis $3200 for new ones. Thanks.

I am looking for a new set of cats and have been considering used/salvage if the circumstances are right (low mileage, etc) -- if not I'll go new/OEM. Fortunately my cats are marginal so I have a little time to make a decision. Doing a search I turned up: 1. Oklahoma Imports 2. DC Auto 3. Parts Heaven 4. There were a couple others that looked smaller but they didn't pickup their phone when I called (so that indicates to me they either don't have their act together or aren't really professional and i don't want to do business with someone like this) Just wanted to ask the community here if I'm missing any others I should give a ring to. Also any opinions on these shops respectively would be much apprecaited. Oklahoma Imports seems very good to me. They said if they had the cats in stock they would be ~ $275ish. DC Auto had them in stock but wanted $750 each (had 40K miles on them). My car is a 3.6L but he said they get $600/each for the 3.4Ls all day long.....which I find a bit hard to believe if Oklahoma Imports is selling them for less than half that. Obviously mileage on the cats has to factor into the price, but still......

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.

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 - 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).

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.

Steve, You would want to look at 4 values: O2 sensor voltage ahead of cat. converter Bank 1 O2 sensor voltage behind cat. converter Bank 1 O2 sensor voltage ahead of cat. converter Bank 2 O2 sensor voltage behind cat. converter Bank 2 Should be very obvious if you sort by "name" in the list of Actual Values. See my post here -- the names are also shown in my graphs: http://www.renntech.org/forums/topic/43522-p2096-porsche-fault-code-16-oxygen-sensor-ageing-delay-bank-1/page-2#entry234549 Bank 1 in fotostar's post above looks bad. Bank 2 looks good.

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.

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

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.

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.

No worries, I definitely appreciate the input so thanks. Will report back later this week when the sensors come and I can do the install (I ordered all 4 but will start with the Bank 1 post-cat first and then log with Durametric again to see if I can observe that constant-like voltage I want to see after the cat). Fingers crossed it's the sensors not the cat$. Either way, I have to say, it does seem very coincidental that both sensors or both cats went at the same time. As JFP said, it could have been something like fouling with bad gas that smoked both of my sensors -- I'm hoping it's not something bigger that's just manifesting itself downstream by damaging my exhaust system. Thanks for your guys' help! Stay tuned . . .

Don't bet against my cats yet. The exhaust does not smell bad at all. On a cold start the post-cat sensors were behaving normally for 15 or 30 seconds or so before they started going haywire. I will replace those sensors and report back with the results. JFP, Thanks for the suggestion on emmissions--I will do this some time this week.

Thanks JFP and Ahsai. Your guidance has been incredibly helpful. Since I couldn't upload the log and RennTech only allows images, I also attached two graphs I created in Excel using the Durametric data and showing the pre and post cat sensors on Bank 1 and Bank2. You can see that it appears the post-cats are following the pre-cats. I will definitely replace the o2 sensors first before even thinking about the cats. Based on what I see here, maybe I only need to replace the post-cats as a first step? It looks like the pre-cats may be ok?? JFP, I saw you said earlier that usually when these sensors go out, it's more often the post-cat. One last question: What would the exhaust stink like if the cats were bad? Would it just have a strong smell of fuel ?

See attached for part of the log I captured from the Durametric (I wanted to upload the whole .csv file but it doesn't look like it's supported). This was captured with the car running and ideling (after the engine was pretty warm). Please correct me if I'm wrong or someone chime in please to check my math: Pre-cats look ok on Bank 1 & 2 but Post-cats data on both banks does not look good. Post-cat readings seems to be following the pre-cats from what I can see. Based on what Ahsai was saying, the cats could be bad. Seems too coincidental that both cats would fail at once so I'm still planning to replace both pre and post cat o2 sensors on both Bank 1 & 2. Everyone agree? One other question I had was with respect to the following. Why isn't the car's computer throwing a CEL now? If the post-cats are bad based on this data, why isn't it triggering a CEL? Since I cleared the errors yesterday evening I've done quite a bit of driving both at low RPMs and at high RPMs, and no CELs have been triggered. Seems like I should be getting a CEL if the post-cat sensors are bad based on this data??