Preludes are not my thing here. So I will try to explain as good as possible.
1990 Prelude 2.05Si
B21 motor
5 speed
Front Steer only

Problem:
Speedo works when car is cold, warms up and absolutely quits and check engine light comes on. CEL must be off to smog car(thanks California)

This does not have a cable driven Speedo like honda shows by VIN

It appears to have a power steering speed sensor and then an electrical speedo take off on top of that.

Questions:
What can the problem be?
Can that P/S speed sensor be eleminated, and how?

 

You just need the speed sensor that sits on top. Unfortunately Honda doesn't appear to carry one and I can't seem to find an aftermarket one anywhere on the net. Your best bet would be to try to source one from the junkyard.

 

Any luck pulling it apart and cleaning it? And thank you for the response.

 

Ive tried doin it myself but i never could get it to work