P0125 Code, replaced coolant temp sensor

[atruepretense]

I've been recently getting the P0125 code, and my car is running rich as hell. I was told there are three things that can cause it, thermostat, Coolant temp sensor, and o2 sensor (weird).

I've replaced the coolant temp sensor and it seems that my gas mileage has increases noticeably, but not to where it should be. I got a spare o2 off my friend and am going to put it in soon, if the o2 doesn't fix it, is it definitely the thermostat. I know it's stupid that I didn't change the thermostat first, it being so cheap, but I figured it was fine.

Any thing else that'll cause this code.

The code means: Insufficient Coolant Temperature for closed loop operation.

 

[tjbiker031]

I would of changed the thermo first

 

[rstchris]

Our cars throw this code when our fuel trims are 20% out for as long as a few minutes. You need to figure out why the car is running rich, fix it then the code will not return.

 

[atruepretense]

Our cars throw this code when our fuel trims are 20% out for as long as a few minutes. You need to figure out why the car is running rich, fix it then the code will not return.

Oh? Thanks a million for telling me that. It was becoming a real mind f***. I just checked my O2, and it seems the wires are messed up right near the sensor. I have an extra, and i'm going to replace it.

Thank you for helping me there rstchris. I was going crazy trying to understand how a coolant temp code wasn't caused by the coolant temp sensor.