Speed sensor cause this?

[LantanaTX]

I did some searching and was wondering if a bad/weak speed sensor could cause, inconsistent idle down when at a stop, no cruise control and inconsistent opening of the secondaries?

When I come to a stop the engine most of the time remains at a high idle but usually finally drops while sitting at a stop light.

secondaries don't seem to always be opening. I have good vacuum.

cruise control doesn't do anything at all. fuse is good.

does the speed sensor throw a code?

What code reader do you recommend? any OBD-1 work? If I use the paperclip method. is the flashing in the LCD disaplay or the check engine light. I also need to figure out why my check engine light does not work. Could it have been disabled somehow? When I turn the key to the on position it does not light up on the information panel.

Thanks for the help guys!