Giving an update on this in case it helps someone in the future. I originally went to the garage expecting to have the crankshaft position sensor replaced. The mechanic I spoke to wasn’t entirely convinced that simply swapping the sensor would solve the issue. Interestingly, he also owns a Superb himself (a slightly newer model, but same generation) and had experienced similar problems. He suspected that the root cause might be damaged wiring, which he said is a common VAG issue on this platform. I left the car with them, and after two full days of diagnostics and inspection, they confirmed that the problem was indeed wiring-related. They found and replaced four damaged wires: One going to the crankshaft sensor Three others near the ECU, which were also causing communication issues They fully diagnosed the ECU, replaced the damaged wires, and ultimately decided to replace the crankshaft sensor as well, since it may have been affected by the faulty wiring or at risk of future failure. TL;DR If you're having intermittent jerks, limp mode, long cranks, or random engine shutoffs, especially if glow plug lights or other systems flash up, don’t overlook the possibility of damaged wiring, especially near the crankshaft sensor or ECU harness. On this generation of Superb, it's more common than you'd expect. Hope this helps someone! Feel free to reach out if you’re facing a similar issue.