C220 CDI: Intermittent Limp Mode Troubleshooting

Hello,
I have another question/problem .
We have a C220 cdi W202, manufactured in 1998, with an automatic transmission. Last week, we drove it on the highway at speeds of 180-190 km/h.
After a short break (I let the engine idle for a while), it suddenly started going into limp mode at 4000 RPM, with the yellow EPC warning light illuminating in the lower right corner.
As soon as you released the gas, it would shut off, the emergency mode would disappear, and it would return to normal, running up to 4000 RPM.
The problem gradually worsened to the point where the car could only travel at 130 km/h. If you went faster, it would go into emergency mode. Eventually, it would turn off again, even when you had your foot on the accelerator (because of the uphill climb). This kept happening throughout the entire journey, and I eventually stopped trying to trigger it.
New day, test drive. Engine exceeds 3000 RPM -> goes into limp mode, but then turns off again...

Does anyone have any ideas or suggestions before I go and read the MB (Mercedes-Benz) diagnostic codes?

Thank you, Phil.

That's quite a description, you could say. It could potentially mean a lot of things.

Make it easier for yourself, and especially for those who want to help you. Check if the entire exhaust system is sealed. How is the fuel supply? What do the filters look like? Does it produce any smoke when running? If so, what color is it? Is the EGR function working properly?

There's a clamp between the turbocharger and the catalytic converter, and it had come loose.
Tightened the screw, so the exhaust system is sealed again, and everything is fine .

Maybe this will help someone someday.
Phil.

PhilXYLON wrote:

Between the turbo and the catalytic converter, there is a clamp, and this clamp had come loose. Tightened the screw, so the exhaust system is sealed again, and everything is fine . Maybe this will help someone someday. Phil

I don't think that was the problem! It's more likely the swirl flaps at the bottom of the intake manifold!
First, read the error codes.