Hi. I’m new here thanks for reading my post. My wife’s is a 207 1.4 petrol 2007. The anti pollution light comes and goes as does the engine light. This doesn’t happen usually from cold but after it’s warmed up a bit. Also when it’s warm it’s started ticking over at about 1500 rpm. After a bit of research I was thinking it maybe a camshaft sensor. However today I took off the oil filler cap and it was full of mayo and I mean full there is a LOT of it not just on the cap but inside too so now I’m thinking head gasket. I read somewhere that not driving it a lot could cause this and she usually does less than 1000 miles a year. Just drives a couple miles to work and back. Any ideas? Thanks for any advice you can offer.