My New Yorker had the head gasket replaced about 3 months ago. I noticed recently oil spots under my car which have started to get larger. The car idles really strange and when I put the car in park it almost wants to die. Just within the week it has started losing power and then will kick in to gear. Almost like the transmission is going out, but I don't think that is the case since my check engine light came on today. I did the code thing and this is what I came up with 12, 13, 51, 22, and 55. Does anyone know what these codes are? Is there somewhere that provides a list? Thank you!