'99 3.4 NOx Emissions Spec

Did use the search but couldn't quite find the info I was looking for.... Having just had success with convincing TFL that my 2002 Honda Transalp falls below the ULEZ NOx limit, despite not actually being Euro 3 compliant, I'm looking into seeing if my 996 might escape the penalty too. Basically I requested a 'Certificate of Conformity' from Honda that showed the NOx emissions were below the Euro 3 level and after sending it off to TFL they have written back to confirm it's now exempt from the ULEZ charge. Result. I know cars need to meet Euro 4 spec to avoid the ULEZ charge (which the facelift 996's already meet) but my early 1999 car doesn't meet it apparently. Cars that meet the Euro 4 spec need to produce less than 0.08g/km of NOx. Question is, without me requesting a certificate of conformity for Porsche at a cost of around £100 (and finding out the hard way that it may not pass the test!), does anyone know what the early 996's actually produced in terms of NOx?

I've been thinking about this. If one were to remap the 996 to achieve Euro 4 would that work? And how hard would this be to do? There are various strategies for reducing nox emissions which wouldn't be that hard to emulate with a modern ECU. However even if you were to be able to do this the the transalp is a motorbike isn't it? I understand there are separate rules created by TFL for motorbikes as opposed to cars - these can be tested individually so presumably there is a bureaucratic route to getting individual bikes approved: Motorbike emissions testing We will also accept evidence from test facilities approved by us for measuring NOx emissions. If successful, the test facility will contact us with the results. Test centres that believe they can offer motorcycle emissions testing to the required standards should email their contact details to [email removed] . Approved centres for motorcycle emissions testing Riverbank Motorcycles Ltd Unit 12, Riverbank Business Park Dye House Lane, Bow London E3 2TB I suspect that there will be significant hurdles to doing a similar thing with a car as there isn't an approved route... But I don't want to be a naysayer and if you can get this done I'll personally send you some booze of some description.

I wasn't really looking to remap the car, although I wouldn't be surprised if that was possible in some capacity, as I think there would be significant expense involved to get it modified and then certified. The Transalp I talked about is indeed a bike. Under ULEZ they are only required to meet Euro 3 specification for NOx (0.015g/km) The 0.08g/km of NOx I called out is the Euro 4 value for cars under the ULEZ rules. The key thing here is that primary measure that the ULEZ is concerned with is the NOx value. As long as you can prove the vehicle is under that specific NOx limit, even if it doesn't meet the official Euro 4 spec overall, then you seem to be able to get an exemption. Hence me trying to find out what the actual NOx value is for those early 3.4 cars. Might just scrape under the limit....

WRT to the remapping I was just musing on the different options really. I've done some googling (as I'm sure you have too!) but not been able to find anything. I'm trying to find the body that does the testing (or sign off) but I guess it might be self-certified and hence not public information...

I think you're right. Porsche self certify the emissions information on a per model/engine basis and the only way to access it is to ask them for a certificate of conformity. This was exactly how it worked with Honda. I think I'm looking to find someone who has already got a certificate for one of those early cars (the certificates are often also used when exporting the car, registering it abroad etc) and seeing what the data is. May also give Porsche themselves a call and ask what the NOx number is. I don't mind paying for the certificate if I can find out what's on it! :?:

If the certificate is required for export is it also required for import too? I had a look about and there are a fair number of 996's being imported from Japan - might be worth contacting the importers to see if they have the details?

Just a quick update to this as I've just been stung with a ULEZ charge - thought it was still cancelled due to Covid but apparently not. As such I've been spurred to action. This useful thread: http://www.boxa.net/forum/topic/80391-986-ulez-compliant/page/3/ suggests that Porsche are handing out certs for free if you get in contact. I've written a very polite email hoping they will do just that. Fingers crossed. I don't hold out much hope however as mine is a throttle cable car with no post-cat sensors so I suspect it won't get below the crucial 0.08g of NOx which apparently is the key to all this. My V5c space for emissions is entirely blank. Anyway will update this thread when something comes up. In the meantime if people are bored and can check if their V5's have NOx information on them I would be interested to see if there is a correlation between passing the ULEZ test page and the NOx numbers on the V5c (especially from early 3.4's).

My emissions info from Porsche. Note that this is a throttle cable car with a manual gearbox. Only one lambda sensor per bank just before the cats. I know that later cars had another set of sensors post-cat which points to better control of emission, I don't know if this was fitted to cable throttle cars. Note that it is definitely worth checking you car on the ulez checker as for some reason some older 996 3.4's are passing. Would be interesting to know why this is.

Just to close this off for anyone else in the same boat as me and shalmaneser. I got the same emissions data as above from Porsche but queried it as it didn't seem to add up correctly. Contacted Porsche GB and they got in touch with the factory and have asked for a bit more info as they agreed the paperwork might not be right. They came back last week and confirmed the initial data they sent me was wrong and sent through some new emissions paperwork from Germany. Sent that on to TFL pointing out that the NOx levels were on par with the Euro 4 spec a couple of days ago and I just got the nod back that it's now exempt. Result! Means I don't have to think about selling her on just yet. Basically I think every 3.4 996 is likely compliant as long as you can get the right paperwork from Porsche :thumbs:

Hi That's interesting. I got a cert of conformity from Porsche (free) for my 2003 2.7 986 Boxster and have posted it off to TFL. It's V5 was also blank for the NOx figures, so was not exempt (it should be). I wonder what the NOx for my 993 is! All the best Berni

What was the new / correct NOx figure, if I may ask? Thanks

New data was: CO - 0.269 HC - 0.079 NOx -0.055 HC+NOx - 0.134 Particulates - 0.000

You're a lifesaver - I live just inside the expanded ULEZ and I've got a '99 996 C2! What evidence did you get from Porsche and who did you have to send it to at TFL? I've just spoken to Porsche GB on the customer services phone line (03457 911 911) and they've advised me to email them and they'll post me a letter with the emissions details. EDIT: I've read through that boxa.net thread and created a "London road user charging" account so hopefully when I receive my "conformity certificate" from Porsche I can just use the "Register a vehicle for ULEZ and LEZ" process on the tfl website!

Just out of pure curosity has anyone looked into this for Turbos. I've been looking at a X reg 01 Turbo and strangely my 996 and a friend's 02 turbo are ULEZ compliant but the turbo I'm looking at isn't. Any ideas from anyone?

I've sent a polite email to porsche UK to request a cert, hopefully they will oblige and I can get this sorted too. Thank you all for the useful advice. One question, are the certificates liked to each specific car, or general based on the model - i.e. 996 Carrera 2? Seems a number have been approved as exempt so would have thought TFL deemed them all approved in that case...