So it all started when i decided i needed a tranny fluid change, i debated between the gm synchromesh and the honda mtf, i picked the sychromesh, changed it, but instead of filling it in the fill hole on the side i filled it where the speedometer sensor goes into the tranny, right after that my speedometer wasn't working and the check engine light came on, i took out the speedo sensor and inspected everything, and everything was good, so i replaced the synchromesh with honda mtf, and that didn't help at all, i tested all the wires on the sensor plug(with a test light), and everything is good, i went to honda and spent 160 dollars on a new sensor, which was only the top part where the plug connects to, after swapping in the new sensor, still nothing, So does anyone have any ideas? could it be the bottom "gear" part of the sensor that goes into the tranny?

oh and the car is a 92 civic SiR, so its a jdm b16 with the y21 tranny(and it has a spoon lsd if that matters)

 

anyone have any idea what could be causing it?