The MIL came on
and the codes are P0426 "Catalyst Temperature Sensor Range/Performance Bank 1" and P1126 "Thermostat Operation". I cleared the codes and the check engine light went off. After a test drive, once all the tests were run, the MIL came back on with only the P1126 code!?!
The Sentra is 2001 GXE with approximately 63k miles. Any suggestions or similar problems/solutions experienced before?
Further, I consider replacing the Thermostat to see if the P1126 will go away. The temperature gauge acts normally (stays close to the center once the engine warms up)
Is the thermostat located at the end of the upper radiator hose or the lower hose?
Also, what might be the reason for a P0426 code appearance? Before replacing O2 sensors or Cat converter I want to know if they are faulty. The dealer tells me that there are 4 sensors at $137 a pop!
Thanks for your help,