I have a 2005 Mazda 3 (SP 2.3), and the check engine light came on. I went out and bought a code reader that told me there are 2 codes. The first being the P0128 code and then the second is showing up as P0128 as well, except there is something that shows up right before the up and down arrows on the right side.
First Question: What is this second code shown below?
I looked around online and found this question that was definitely helpful on knowing what to look for. Since I imagine my coolant level is just fine, my Second Question: Should the problem be the thermostat itself, where is it and how do I change it?
UPDATE: I have confirmed that my coolant level is just fine, within the min/max levels. Do I need to jump to changing thermostats, or should I flush the coolant first?