Unfortunately I have no fault codes. Citroen are very secretive about there paperwork and don’t give you any information only a quote for the part you need and the price. The garage I just went to showed me the readings when it was at 2000 revs but they said the fault came up as the oxygen lead yet again so they replaced that part. Will give it a go with what you’ve suggested and that’s for the reply.
This has been an ongoing problem on my C1 2015 model since before 2020. After going to 2 different garages with the problem and these garages only fixed the problem temporarily I decided to take it to my main Citroen garage to get a diagnostic test. They found that I needed a new oxygen sensor cable and I had this fitted by my own mechanic who has looked after my cars for years but within 24 the 3 lights came back on. I took it back to Citroen again to then be told it was the ECU board and this would cost £1700. I then took it to another garage who specialises in Citroen to be told the oxygen