should I replace my 4.2 FSI injector o-rings?
 

Hello everyone,
my 2007 Q7 has had a misfire problem for a while now. I have had the dealer try to diagnose it and I feel like their just throwing parts at it, and its not fixing the problem. It has 110k on it and it have never had a carbon cleaning so i'm going to clean the valves this weekend and see if that fixes it. My question is does anyone know if there is a way to check the injector seals? It would be nice to know if I need to replace any of the seals while the intake is off so I don't end up pulling it a second time.