sometimes when I use my car the transmission won't even shift I usually have to put it in neutral and back to drive and then it will start shifting, but a little late. And it always is a little late on the shift, check engine light was on, but then is now off after driving it a bit. I have been doing some research and was wanting anyone's oppinion if the problem could be the transmission sensors. Also, if this turns out to be a problem that I can't fix without buying a new transmission, is it possible to install a manual transmission into my car instead of the automatic. Thank you.