1,4 TDI: AGR-Ventil & Lambdasonde defekt? | Posts 32+

So, I see something that can be unscrewed, where you can preferably take measurements.

Did you actually drag that thing around with all those cables and hoses attached, scraping it along the ground?

If that's the case, it's better to have a workshop do the job instead of continuing to cause further damage.

dieselschrauber wrote:

So, I see something that can be unscrewed, where you can measure properly. Did you actually drag that thing around with all those cables and hoses attached, scraping it along the ground? If that's the case, it's better to have a workshop do the job instead of continuing to cause further damage.

Of course not, Rainer!
What do you think?

Okay, then I'll check the engine side. It's not possible to access it from the other side.
I thought it was important and only made sense to measure from both sides.

Thank you!

My measurements indicate that the chambers are between 50% and 90% empty (possibly even 100%, as I can only estimate the exact length of the chambers).

It's not that bad, is it?

You don't know how long the ceramic material is inside, so a USB endoscope inserted through the exhaust pipe would be helpful, or you could try searching online for images of your specific type of cut-open DPF.

It might be possible to insert a garden hose into the exhaust pipe and observe when it reaches the differential pressure sensor connection, allowing you to estimate how far it can be inserted towards the ceramic component.

It's not about the 5mm; it's about whether 10%, 40%, or 90% of the ceramic is exposed.

In some previous posts, you mentioned acquiring a G450, but you didn't specify the outcome or whether the maximum differential pressure and offset values changed.

I've reassembled everything in the meantime, including the new G450.

I set the ash mass to 10g and trained the G450 using the five-cycle ignition-on-ignition-off procedure.

So far, there have been no further error messages, but I've only driven about 120 km. I haven't yet taken any measurements of differential pressure and offset. Does this measurement necessarily have to be performed under full load?

Today, I wanted to check the differential pressure. Strangely enough, it was "0," whether the system was turned off or during operation.

Since I also had a short circuit in the error memory, I checked the wiring of the G450. And sure enough, there was a broken wire!

I found a wonderfully functional tool for removing the pins: an LED! The wire of a paperclip was too thick for this connector. I soldered a new cable onto the remaining cable stub and covered it with heat-shrink tubing.

"And so, I once again had readings from the differential pressure sensor."

"I'm adding this here. Can you interpret it for me?"

Thank you very much!

A brief update on the results of the DPF cleaning:

After driving almost 2000 kilometers, I've noticed that the regeneration cycle of the DPF has extended to approximately 450 km!

Thank you for the feedback!

Hello everyone,

I finally managed to pressure test the intercooler system!
Result: everything is sealed tight!

I read elsewhere that a faulty oxygen sensor could be responsible for the "mixture too rich" error.

What do you think about it?
Is there a way to measure the lambda sensor using VCDS in some way?
Or should we exchange them directly?

Hello everyone!

I replaced the oxygen sensor in my Polo this weekend.
And indeed, the original error has not occurred again so far (signal too strong)!

So, maybe this is also interesting for everyone else who's getting the same error message!

After 422,000 kilometers, you can certainly replace a probe like that sometimes!

Thank you for the feedback .