The sensor on the thermostat housing only activates the radiator fan. It has nothing to do with controlling the engine. The sensor in the head below the distributor, the one with two wires, is connected to the ECU.

 

my buddie has this exact problem in his 97 HB he did everything you did and finally replaced the computer, now it runs great, hope this help

 

thanks for the tip, but Ive tried 3 computers, none of them make the car run any better after it warms up and enters closed loop. anyone wanna buy a 97' dx?

 

I'll give you a 140cm park snowboard, a 156cm all-mountain snowboard, and a Haro bmx bike for it

 

I dont snowboard anymore, lol. Is there a way I can test my ICM? there is no auto parts store in my area that tests parts, other than batteries. And is it normal after driving the car, and having it to full temperature to have the lower radiator hose cold still? while the upper is mad hot? My civic is still misfiring constantly when its warm, and the tachometer drops to zero, then goes back up to 2 or 3 thousand while driving (when its misfiring it goes to 0 and the throttle does nothing at that point, car just bogs out.)