Golf 4 1.6 SR APF - Lambda sensor error?

Hello everyone,

I need help! My Golf wants to annoy me .

The error codes P1176 and P0170 are repeatedly appearing in the diagnostic trouble code memory (see attachment).

I therefore ran several tests, and two things caught my attention:
MWB 41 - The pre-cat probe is not showing any resistance, but otherwise, the values for this probe appear to be okay according to MWB 30 and 33.

MWB 43 - Allegedly, the post-cataract probe is not functioning correctly! But I don't understand why

Can you extract any information from the data?
Initially, I suspected the post-catheter, but now, the pre-catheter is extremely concerning to me.

Sure, no problem! Here's the translation:

"Thank you in advance!"

Please provide the text you would like me to translate from German to English.

Unfortunately, the automatic scan feature wasn't working due to a gateway issue, so he had to manually select the model.
I've also included the readiness scores.

I hope you have a guess .

Hello,

I would first check if the engine is running too lean or too rich, and then adjust the troubleshooting accordingly.
Okay, I'm ready. Please provide the German text you want me to translate.

Best regards, Rainer.

According to VCDS diagnostic data, the lambda control for the upstream oxygen sensor operates within the range of -6% to +5% during idle.

According to my information, it's actually fine, so it's neither too fatty nor too lean.

The LMM values are also excellent, except for the altitude correction value, which averages -5.5%, meaning 550 meters of elevation gain, even though I live at an altitude of only 5 meters. I temporarily installed a new, genuine mass airflow sensor (MAF), but the readings are exactly the same.

Then, I would continue investigating, using error code 16554 as a possible cause. Possible causes include insufficient fuel supply, faulty sensors, or malfunctioning probes.

I don't understand how you're dealing with the 5% incline at an altitude of 550 meters.
When the LMM (mass airflow sensor) measures the air mass, the altitude at which you are located is also irrelevant.

If the mass airflow sensor (MAF) measures less air mass than expected, I would look for air leaks behind the MAF sensor.

Best regards, Rainer.

Today, I disassembled the oil filler neck because it was slightly leaking at the bottom, and I wanted to replace the gasket. It almost came out easily when I removed the intake hose. It was definitely not sealing properly. It's broken on the underside, on one of the closure sides - see the picture.
Could that be the cause?

Probably not; if the engine is drawing air past the pistons, it's already in bad shape. Is the compression okay?

Hello...

Is the lower part of the oil filler neck also the outlet for the crankcase ventilation system in this engine?
It then goes directly in front of the engine control unit (ECU) into the intake hose, specifically after the mass airflow sensor (MAF). If there are cracks, it causes air leaks.
In addition, there's a membrane in the connector that is prone to cracking.
Then, air from the tax system line enters areas where it shouldn't be.


Regards, Mpire.