Quick background: I own a 96 civic dx m/t. No mods its just a commuter car to get me back and forth to work however I always took care of the car. Last week the speedometer/odometer just stoped working but every now and then it would come back on and work fine. Temp and Fuel always works fine regardless of the speedometer and odometer. After reading posts on here I assumed it would be the speed sensor so I replaced it, which was easy and cheap. However the same problem kept occuring. So I went to Autozone and had the codes read. I got P0420. The car has been driving and running fine. I dont hear any rattlings. But its just really anoying I've never had any issues with the car and I don't really have the money to put into it. Also I just had emmisions done on it three weeks ago without any issues. Can anyone help me? Thanks!

 

Since the speed sensor was replaced, your problem is the GAUGE CLUSTER.

 

Id check your under dash fuses

 

i was having the same problem with my speed sensor and it was some very bad corrosion in the speed sensor connector. I replaced it with once from the junkyard and covered it with di-electric grease and its great now.