Check Engine Light Code: P0128
Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)

Replace Thermostat: the new thermostat will come with the thermostat housing and the sensor all in one.

Remove battery
drain cooling system from the bottom of rad, (coolant drain)
Bolt OFF, and ON,
and then purge the air from the system, (Burp system) by letting it run a bit without the coolant cap.

**** Careful****

Do NOT drop any coolant on the bell housing (try to keep transmission dry)
If you have a 5 speed you could contaminate the clutch friction material and your clutch will judder and slip on release.