Began having issues with my 99 civic slipping out of gear. It will shift into gear and drive fora few feet and slip out of gear like it's in neutral. The fluid is in normal range and the solenoid seem to be operating fine. I did add some generic automatic transmission fluid (about a quart and a half about 3000 miles ago) is "Honda" fluid required? And could this be part of my problem? Thanks for any help