Had to have my 2005 Limited with 105,000 miles emission tested to day. Pass ok with no problems. 30 minutes later stopped at a store. When I came out it started and ran ok but check engine light on and would not go out of park. Used tool and moved to drive ok. Remained in limp mode, still starts in neutral or park. Search of internet says faulty Park/Neutral Position Switch or speed sensor. Code with OBD II Scan Tool shows PO705. I don’t want to take it to a transmission shop if I don’t have to. I am handy but don’t know where to start. Would be thankful for any help.