Skoda Karoq Engine Issues

I had a similar issue with my Skoda Octavia; the symptoms you describe are quite familiar. The rough idle, check engine light, and especially the loss of power point towards a malfunctioning EGR valve. Have you checked for any vacuum leaks in the EGR system? Also, is the hissing sound constant or only during specific engine loads?

Thanks for the quick reply. I haven't specifically checked for vacuum leaks, but I visually inspected the hoses, and they seem okay. The hissing is definitely more pronounced under acceleration. Did you also experience smoke when accelerating? And did the issue affect your catalytic converter?

Given the hissing under acceleration, it's highly likely a vacuum leak within the EGR system, making the valve's malfunction worse. I experienced similar symptoms; the smoke was intermittent but definitely present. In my case, the catalytic converter remained unaffected, but prolonged EGR issues can certainly lead to catalytic converter problems due to incomplete combustion. Considering the mileage and symptoms, I recommend having the EGR valve professionally inspected and likely replaced. Continuing to drive it in this condition may cause further damage.

It was the EGR valve, like I thought. Replaced it, and the Karoq is running great again. The catalytic converter seems okay. Total cost was 355€, parts and labor included. Thanks for the help; it helped me be sure before taking it in.