My son and I had plans to change the oil in his Corolla today.As so many times before he crawled under the car and removed the drain plug,so I thought.We then changed the filter,added the new oil,and started it up to look for leaks.This was at about 9 am this morning.Well,I layed down to take a nap about 2 pm.He came in my room,paniced,and said his CEL was on,the car ran sluggish,and it shifted funny! First thing I did,for some odd reason,was check the oil.It was about 3" above the full mark! I told him we needed to drain some oil and go from there.This time I crawled under the car and started to remove the drain plug.He says,"why are you removing that plug; its the other one,rite?" Reality then hit me like a ton of bricks; he drained the tranny fluid earlier! Now I knew why it was shifting funny,over filled with oil,and running like crap! The extra oil had got to number 2 plug and fouled it out! I knew this from scanning the CEL and came up with code PO302.Long story short,we added the correct amount of tranny fluid,drained the oil and added the correct amount,and changed all the plugs.It runs smoother then silk! That is what I call a major brain fart on his part!