Civic EG

is there a way to test the sensor and see if its bad ? every thing works in the cluster just no speed lol every mow and again it jumps then goes to zero. and a cel pops on every now and again and goes off so what could this be?

sounds like the speed sensor to me. it will throw the CEL. but if the speedo never works and the CEL is not always on i would imagine the speedo could be faulty aswell

i want to try the plug maybe a bad connection

Yeah jack the front wheels off the ground and probe the speedometer output (usually blue). Ground the black probe to the battery or chassis. Spin the wheels by hand and look at the AC voltage. It should increase with speed.