Hello bloke , first up the gunk you notice is blow bye and is perfectly normal !! Clean it out and reset your ECU - just disconnect the neg lead on the battery for about 10mins , and presto car should be good as new.. Tip some WYNNS spitfire cleaner (about $12.00) most shops in your tank every 3 months , injectors should be fine !! How many k,s has she done , more than happy to offer advice mate EDIT : Do you have TWO user names ??