UKH

Hi, on 3 occasions my engine warning light has come up and on the 3rd occasion there was a loss of power and really loud engine noise. I’ve taken it to the Peugeot garage and they’ve told me they are not sure what the problem is because the diagnostic says cylinder undetermined which makes me worried because it means I have to take the risk and drive it. Does anyone have advice on what the problem could be. I’ve had a full service two months ago and already got new spark plugs 

Golly - UKC us good, but that's ambitious.

What did the garage propose?

Given the noise and loss of power I wouldn't drive it. Inconvenient and expensive for them to take the lid off and solve, but a cheap magic bullet from outside that allows you to keep driving it seems unlikely.

I know it's not what you want to hear - sorry to not be more encouraging.

Get on to a Peugeot forum, someone will know off by heart.   Sounds like the belt had jumped a tooth and has now jumped more causing valve damage.   Main dealers are usually the last place to go for engine damage as they are "new engine afraid sir"

I had a 208 about 15 years ago. It had a nasty habit of eating injectors. Rather costly to replace unfortunately.