Peugeot 208 Camshaft Sensor Issue

That sounds nasty! P0341 points right at the camshaft position sensor. First, did you scope the signal from the sensor itself? A wonky waveform can tell you a lot. Also, have you checked the wiring harness and connector for any corrosion or damage? Sometimes it's a simple fix like a bad connection throwing everything off. Ignition timing could be all over the place!

Good call on scoping the signal - I haven't gone that far yet. What kind of waveform am I hoping to see, and what should I be looking for that screams 'problem'?

Right, you want a nice, clean square wave. Jitter, dropouts, or a generally weak signal indicate a failing sensor or, as you suspect, issues with the encoder wheel. Since you have high mileage I would not rule out that the encoder wheel could be damaged, or maybe even that the timing belt skipped a tooth. But considering your symptoms, it's probably best to get it to a shop. Repair cost will be somewhere around 695€

Appreciate the insight! I took it to my mechanic, and you nailed it. The encoder wheel was indeed the culprit, and the camshaft sensor was throwing a fit because of it. Now I can finally rest. Thanks!