1999 sebring
 

I have a 1999 seabring that just stared missing 3rd and 2nd gear. trans fluid is good. I added lucas to it to see if it would help but thats a no go. The codes say po733. It is really cols and i had no problems before this. The rpms get up to about 3 grand and then it shifts. anyone have any ideas what this could be..?