NOx Sensor Replacement

tbayers

So have a 171 Dispatch. Had a flashing adblue warning light and a fixed service and ecu light came on a few days ago with a 1100km "can't start warning" . Brought it into citreon dealer and they ran diagnostic and said NOx sensor needs replacing and then a forced dpf regen. They are known to go, not ideal but it happens.

Next question is, should it be OK to bring to my local mechanic? First time I needed him in a while as had warranty with van since purchase. I'd rather not pay crazy dealer labour prices for a relatively simple job. But my main worry is, will my local mechanic's fault reader be enough to reset the codes too?? Or can dealers ecu readers only reset certain codes? Citreon also said from their experience this issue has been known to bring up other issues when the sensor is replaced and a further set of tests will need to be carried out. But they have a local reputation of fleecing anybody that goes in there so trust is hard to attain tbh...

I never trust the scan tool diagnostics, because it is only DTC reading, not the real diagnostics. Even 5 year old child can read for you DTC codes. If they have solid proof, go ahead and replace the sensor. If they are not sure and like to play swapnostics, be 100% sure it cost no prats for you if they can not fix. Also keep the old part short time around because new part does not mean automatically it is good part.

tbayers

https://www.boards.ie/discussion/comment/118424974#Comment_118424974

So might be no harm to have local mechanic have a look at it? Just surprised these things fail so early. Only have 93k kms done

Ask from local car mechanic (not me), they have all wiring diagrams and all test equipment. If they do not have, no point to play a fool. I am sure they can force the regeneration because these days every garage have a bi-Directional scanners. Do not pay insane money for that simple job (short time driving). Who knows, after successful regeneration the sensor may wake up too. That last part is wide guessing, not scientific diagnostics.

If you read the user manual, there should be the conditions how you can yourself make that regeneration. Typically the speed must be over X km, tank X amount fuel and X rpm. Do not drive on small and slow roads. If temperature falls too much, it stop regeneration.

tbayers

Thanks for your input. As I said, the local dealer garage in question has a reputation of just replacing stuff rather than fixing (swapnostics as you so rightly put it).

And very good point re the regen and then sensor potentially waking up.

At least it is worth to try DIY first. Until you do not ignore any important messages on dash like too high coolant temperature, low oil pressure etc, it should be ok DIY natural regeneration. If you get to traffic jam or too low speed traffic you can keep rpm up but turn AC to max. It force the cooling fan to operate by full speed. Remember, that last part is only short term solution to avoid stopping the regeneration. You can not to do it too long time, car need to move to keep engine temperature on safe range.

tbayers

Turned out to be a faulty Nox sensor. This was replaced and errors went away.

Kochanek

How Much was the Repair cost ?