Speed sensor dash light

There's no such thing as speed sensor warning light. If you are referring to the red Check Engine light, there are dozens of defects that can be detected. If a defect refers to something that could adversely affect emissions, the Check Engine light will turn on.

The place to start is by having the diagnostic fault codes read and recorded. Normally the people at most auto parts stores will do that for you for free, but they can only read them on '96 and newer cars. You will need to find a mechanic with a scanner that works on a '93 import model.

The fault code will indicate the circuit or system that needs further diagnosis, or the unacceptable operating condition. They do not ever say to replace a part or that one is bad. When a part is referenced in a fault code, it is actually the cause of that code about half of the time.

The "Battery" light is different than the red Check Engine light. I'm not familiar with the green light. Any chance you have the owner's manual?

What model and engine size do you have?

How did you arrive at your user name? Are you a fan of Last Man Standing, like I am?

Oxygen sensor codes are set in the Engine Computer. There are dozens of them and they mean very different and specific things. Don't waste your money on an unneeded oxygen sensor. That will just lead to disappointment when the green light is still on. Check Engine lights are always red or yellow.

Being a green light you're seeing, that implies it is related to something not serious. The only thing I can think of goes back to the late '80s and early '90s when some cars had a "shift" light on the dash. Those were only used with manual transmissions. People thought they would get the best fuel mileage if they up-shifted when the light flashed on. In fact, the light did turn off each time you up-shifted, but that wasn't it's purpose. The actual purpose of those lights was for emissions testing. If you drove the car normally without paying any attention to that light, there could potentially be brief moments when emissions jumped too high. Rather than using common sense, that was enough for the politicians to have a hissy-fit and require pounds of solution for an ounce of trouble. Instead, the engineers put that "up-shift" light on the dash to tell the inspectors how to drive the car for testing. If they up-shifted the instant the light turned on, which was a little too early for comfortable driving, it would pass the emissions tests. This is a classic example of where the politicians, who know nothing about cars, were satisfied, and their goals were achieved, but a momentary glitch could wipe out common sense.

This didn't apply to cars with automatic transmissions, and it never stayed on steady, so I'm back to researching what your light is for.