so my 1990 crx si had a check engine light about a month ago, code #6, faulty temp sensor, or thermostat, i replaced the thermostat with a Honda one, added fresh coolant, and it went away. now its back, and i noticed after a long drive the bottom hose wont get warm and the CEL comes on and off like every other day...the heater blows cold too but the upper radiator hose gets hot...any ideas?

also the previous owner messed with all the temp sensor wires, its all alligator clipped together, says that has triggered a CEL before and to just wiggle them around, or fix the wires, but the gauge works as far as i know.

 

Your heater core could be clogged. The bottom hose isn't supposed to get hot, Its the fluid coming out of the radiator that is cooled, ready to go back into the motor.

 

Code 6 is for the ECT. It's the two prong round sensor on the side of your head near the distributor. You also need to properly bleed your cooling system when doing any procedure that involves loss of coolant.