Calling all Noxem owners

[teddy1600]

Looking for some real-life experiences... About to order one of these but intrigued whether people followed the fairly rigorous reset adaptations processes or whether they simply coded a replacement NOx sensor (and NOx Cat, if applicable)?

I'm based in South London and haven't spoken to an independent who has instilled too much confidence that they would (or could) follow the procedures properly so interested to hear if people have coded a new sensor and then let the DME work the rest out over a series of varied runs?

And if anyone has any indy recommendations around these parts who will (or might) be up to the job I'm all ears; probably willing to travel to N London/Kent/Surrey for the pleasure.

Thanks in advance.

[pmorg4]

I'd assume you'd need to code a new NOx cat to get rid of the cat ageing stored in the ECU, although clearing the fault codes might be enough. The worst that can happen is that you'll fail to resolve the issue and the ECU still records a cat ageing fault (which you can sort out later).

If you're buying the NOXem from Bimmerprofs I'm sure they will tell you what procedures need to be followed, as they seem very knowledgable on this kind of thing.

[teddy1600]

Thanks pmorg4. I should have specified - yes, I am looking at Bimmerprofs. Their website provides plenty of detail on the installation and coding process but seem to allude to two methods, both involving encoding a new cat (if you have 30E9 code - I do) and deleting fault codes. The variation seems to be either:

- Encode a new sensor, or
- Follow the reset adaptations procedures stated on the website

Just wondering if anyone had followed the first route and how successful it was...

[markirl]

If it helps I've had a 30e9 code for about 60k miles without any issues - still goes into strat mode etc.

[teddy1600]

Interesting, I didn't realise that was possible. I also have NOx sensor error codes as well as mixture control codes so it seems time to replace the sensor, not least as fuel consumption isn't great (~25mpg, 50/50 mixed city and long runs, occasional spurts of joy).

I've booked it in for next week so we'll see how it gets on. Will get them to code a new sensor and cat, reset adaptations and delete fault codes; then I'll do some varied runs for 100-200 miles.

[teddy1600]

Just to tie this thread up and in case anyone is interested in future, the Noxem installation was a success. I got the garage to install the sensor, code a new sensor & cat, delete adaptations and fault codes. I then took it on some runs to semi replicate those instructed on bimmerprofs but otherwise drove it as usual.

It was a bit of dog for 50 miles or so as it started relearning ful trims but gradually smoothed out over the next 200-300 miles, culminating in a London to Cornwall trip seeing 37 mpg (up from ~26).

What was even more pleasing is that it has (whisper it) also resolved my cold start, lumpy idle issue with the high pressure fuel system and mixture control error codes not returning. I had always suspected these and an EML at high temps (engine and atmosphere) would be sensor related and the NOx has a large effect on how these N53's run. Whilst I had a theory, the codes had always concerned me that it was HPFP or injector related, fingers crossed they stay away.

Well done Bimmerprofs!

[Touring442]

That is good news.

I wonder how many 'injectors knackered m8' problem cars need one of these?

[Stefcool1]

Help needed!! Fantastic to hear the NOXEM worked and also removed your 30D9 cat code!

I’m based in south London, could you share the garage that fitted and coded the NOXEM for you? I have all the relevant programs to do it myself but don’t want to mess it up somehow.

Thanks!

[Fiedka]

I am still baffled by the Noxem or rather benefits of installing it and genuine new sensor for that matter.
My nox sensor was dead since I bought the car but I easily get 38mpg on 70-80 mph run.
Short runs in traffic with very heavy foot end up around 25-27 mpg.
This feels very good for 272 3.0 liter engine and makes me question the fuel improvements with nox sensor working?
My exhaust is not sooty at all either.
My local BMw specialist (BMwMAn in Heanor, sadly no longer in business) always said replacing sensor won’t change fuel economy. Only aged cat will affect MPG.

[pmorg4]

Fiedka said:

I am still baffled by the Noxem or rather benefits of installing it and genuine new sensor for that matter.
My nox sensor was dead since I bought the car but I easily get 38mpg on 70-80 mph run.
Short runs in traffic with very heavy foot end up around 25-27 mpg.
This feels very good for 272 3.0 liter engine and makes me question the fuel improvements with nox sensor working?
My exhaust is not sooty at all either.
My local BMw specialist (BMwMAn in Heanor, sadly no longer in business) always said replacing sensor won’t change fuel economy. Only aged cat will affect MPG.

Those figures are achievable with an N52 330i which is far more reliable with its indirect injection, no HPFP or NOx gear etc. The advantage of the N53 is stratified charge mode which allows much leaner ratios and hence better economy at low to mid loads, but due to increased NOx will only be enabled with a working NOx treatment system. Not sure where your specialist got their info but if the ECU isn’t seeing plausible data from the NOx sensor it will disable stratified mode.

Even my N54 335i will get into the mid-high 30s on a motorway run. A good N53 should be well into the 40s.

[preacherman]

Stefcool1 said:

Help needed!! Fantastic to hear the NOXEM worked and also removed your 30D9 cat code!

I’m based in south London, could you share the garage that fitted and coded the NOXEM for you? I have all the relevant programs to do it myself but don’t want to mess it up somehow.

Thanks!

It was Chelsea Autoworx. I left them with a print out of the Bimmerprofs instructions just to make sure there was no ambiguity but the guy seemed confident.

[preacherman]

Fiedka said:

I am still baffled by the Noxem or rather benefits of installing it and genuine new sensor for that matter.
My nox sensor was dead since I bought the car but I easily get 38mpg on 70-80 mph run.
Short runs in traffic with very heavy foot end up around 25-27 mpg.
This feels very good for 272 3.0 liter engine and makes me question the fuel improvements with nox sensor working?
My exhaust is not sooty at all either.
My local BMw specialist (BMwMAn in Heanor, sadly no longer in business) always said replacing sensor won’t change fuel economy. Only aged cat will affect MPG.

The problems occur when you have the code for a dying NOX cat which usually restricts the ability to go into stratified mode. If you only have a dying sensor then in theory you could replace with a new genuine sensor and should be back to normal running. In reality, the cat will be on limited time and BMW sensors aren't cheap so you could be back at the same point in the near future.

[Fiedka]

Yes. I was going to give BMW sensor a go as car has only done 29k miles but will probably go noxem route and see if I further improve mpg.
Any ideas on specialists in East Midlands that can do adaptations?
I have right cable and inpa so worst case could have a go myself but admittedly worried that I will mess something up.