I have found out that the reason my Superb was in emergency mode , is because I had an injection problem ,acording to our computer test rig . After pulling it out  , with the biggest slam hammer on the market , I found that the end of the injector was rusty ! Is this normal ? Then I took the other 3 out , number one was , to my eyes  had slight oil on it , nothing seriuos , but all the others , and two of them where running fine , where rusty . The car was running perfectly up till then . Good starting , good mileage etc .No smoke .I have been given a used injector from  an accident car , with only 1500 km on it .Just to try it out . Hope you can help , and maybe some words of wisdom !! Thank you Harry  

I have just been told by a grownup ! That be happy , not with the rusting in the bore side , but that its a sighn that it did not leak diesel and the one you thought was healthy , ie , had a light oil covering is a sighn that the injector was not air tight ! And the number two injector is probably blocked , and take the end that goes into the cylinder take it apart , with the help of one trustworthy YOUTUBER , and clean all the jets out clean all the parts and clean all the rusty surfaces on all the injectors and coat with ,Ive been told , a silicone type lubricant .Any thoughts ? Please let ne know .Thanks Harry