I have ek civic and my cluster mphs goes up and down even if am not driving. I was wondering if i need to change my speed sensor, and where is that located at?
Also i have two clusters a si and my stock one and when i put each in my car the Fuel/Temp Gauge dosent work for both, do you guys know what might be the problem?

 

check your wires on the speed sensor and it's locate at the tranny.
on the fuel/temp i would also check for the wires and the sensor.

 

if that doesnt fix it get a new cluster. these go bad

 

i had the same problem about a month ago. pull out the plug that goes to the speed sensor and try cleaning it. mines was going crazy because it had water when i went through a flood. after i cleaned it the code went away and the speedometer started to work normal again.