AGR Problems with CAYC After Just Over a Year

"In our Skoda Octavia, manufactured in 2012 and with over 206,000 kilometers on the odometer, the AGR cooler and AGR valve were replaced a year ago because the AGR valve was stuck. As far as I know, it wasn't an original part, but rather something from the parts supplier Stahlgruber."
Prior to that, the car was driven for approximately 5 years, mostly on very short trips of about 1 kilometer, occasionally with trips of 15 kilometers, and roughly every two months, it would cover a distance of over 1,000 kilometers in two segments.
After a year of changing the driving profile, meaning the car now usually drives 20 km instead of just 1 km per day, the EGR valve failed. Now, after another year or so, the EGR valve is stuck again, but only after a trip of about 100 km.

Could the change in driving profile negatively affect the exhaust system, specifically the EGR (Exhaust Gas Recirculation) system, or could other factors be responsible?

There is no stuttering or interruptions. Only shortly before the engine goes into emergency mode does it experience a slight hiccup.

Before I start working on it myself, I'd like to first find out what the potential cause might be.

The workshop that replaced the part had the car back in their possession just a few days ago and returned the car with the words: "We cleaned the AGR valve, and the error should no longer occur." But I don't think anything was actually removed, because the repair seemed too quick to me... They also didn't want any money for it .
But after 2 weeks, meaning today, the same problem has occurred again!

Hello,

Depending on the engine, the EGR valve can be installed in various locations. Most often, the valve itself becomes weak and starts to stick.
If it's installed incorrectly, I would only use an original part due to the amount of effort involved.

Best regards, Rainer.

Unfortunately, it's so integrated that the entire cooler needs to be replaced.

Yes, but do the exhaust system, DPF (Diesel Particulate Filter), driveshaft, and several hoses need to be removed?
Hours of work just to get there.

Unfortunately, it already is for me. I would make that dependent on the amount of effort required.

Definitely the driveshaft, hopefully just the exhaust pipe is loose. Also the hoses, because it's water-cooled.

I checked the parts catalog from Stahlgruber. It only lists a radiator with a valve as a product of Hitachi.

"Can you recommend them? I would personally only buy replacement parts from Pierburg, as I've never had any problems with them. But as I've learned/personally experienced, the original parts tend to last longer."

Sure, here is the translation of the text from German to English:

"PS:"

Can low-quality diesel contribute to this part failing faster because it produces more soot?
"Because for the last few fill-ups, I had only been using diesel without any biofuel additives in my VW Caddy. Unlike regular diesel, there's no more smell coming from the exhaust when you stand behind the vehicle. Also, I can't hear any knocking or pinging anymore."

According to my research and experience, soot plays a less significant role; rather, the problem lies in the poorly designed construction of this valve, made with the cheapest materials.

Whether it's plastic gears or loose screws... It's just JUNK, pure garbage!

Fortunately, the part was still covered by warranty and it was replaced.

Recently, I managed to free up the valve using a throttle body cleaner. I'm not sure if it was the cleaner that did the trick. However, I ran a diagnostic test for the actuator during the process. Initially, you could hear the valve squeak briefly, and then it seemed to be clear. Perhaps it was also because the cleaner provided some lubrication? Everything worked fine at first, but suddenly, instead of a sporadic AGR (Exhaust Gas Recirculation) error, the fault code indicated a malfunction of the AGR system. Hopefully, it's just a manufacturer defect, and it has been sticking slightly all along.

A new AGR valve for a VW costs €632 here in Germany, including seals and all the necessary hardware like screws, when purchased from a VW dealer.