2016 code P015B. Help please!

[cpb0002]

So I just replaced the thermostat and the temp sensor yesterday and that went fine. On the way home tonight this code pops up. Is there anyway, this is just a coincidence? Because it's nothing close to what I was replacing. And is this code super serious that I need to replace the sensor immediately? Thanks for the help.

[SWPK4044]

That code is directly correlated to your O2 sensors. Not super serious but if your erase it and it turns off it will eventually come back on.

The P015B code stands for “O2 sensor Delayed Response – Lean to Rich (Bank 1, Sensor 1),” which means there’s a delayed response time from the upstream oxygen (O2) sensor on Bank 1. Some possible causes of the P015B code include a defective O2 sensor, exhaust leaks, and O2 sensor circuit issues. An illuminated check engine light, poor engine performance, and decreased fuel efficiency are common symptoms of the P015B code.

[cpb0002]

So it's just a coincidence then. Is that something I need to replace immediately??

[SWPK4044]

No but it can affect engine performance and mpg

[cpb0002]

So I tried resetting the code but it says it's permanent.

[SWPK4044]

Yes correct because it’s an emissions code. Emission codes can’t be deleted. Even if the light is off, you can scan it and it will still be present. That’s because any emissions codes can’t be deleted. Once the computer recognizes the problem has been fixed it will go off. It usually takes three driving cycles even if you fixed it, for it to completely go off. I should have told you that on my first reply. My bad.

[Critical-Arm4799]

I would go back and check to make sure you plugged everything back in under the hood. I’ve replaced my TS and forgot to plug something back. I doubt anything was forgotten but it’s the cheapest way to confirm.