Hi my vw golf tsi 1.4 has just failed on the following. 

Exhaust hydrocarbon content after 2nd fast idle

Exhaust monoxide content after 2nd fast idle

Lambda reading after 2nd fast idle

Can anyone tell me what parts have gone or worn out. My mot garage who I have uesd for a few years now have had to take it  to the main dealer  Ian 

I would certainly check all ignition components and also check for any exhaust leaks.

Hydrocarbons are unburnt fuel particles e.g. the ignition (or engine) isn't burning all the fuel efficiently

 

Thanks for that will get checked out 

I thought off crap petrol just found out tesco petrol not the best so going to use esso from now on. Thanks again