I have a '96 Civic EX 4 DR with an Automatic tranny. I can drive the car for about 15 miles, then when I decelerate, sometimes it slips out of gear, like it's in neutral. Sometimes you can get it back in gear by revving the engine, sometimes you can't. However, if you turn the car off and on, it will drive fine for another few minutes. The speedometer is not working at all. Is it a faulty speed sensor? Or a more serious problem?

 

you need a new tranny, you could try a tranny service i guess (filter and fluid change but i dont know it would help), as for the speedo thats probably the vss sensor