P0125 code

My 2000 Tundra code above with normal coolant temperatures. I checked coolant level and it was a bit low but above low mark and below F so I filled to the F. I went ahead and replaced the thermostat as it was a bit rusty and decided to replace the ECT as well. After a test drive it's throwing a P0125 code? I did some more digging and noticed with a freeze frame my fuel trim for bank 2 is -0.78125% Vs bank 1 showed 2.34375%. The coolant temp was 205 F. I will upload the freeze frame here. Has anyone had this and can give me more insight. I checked for leaks and don't see any at this time but have ordered a pressure tester and will get that soon.

I was reading somewhere on the net that some Toyotas will show problems with this code and a oxy sensor code but as of this time I have no other codes. Thanks Ya'll

 

Which ECT did you replace? The green one or the grey/black one? There's two, side by side in your year, to the passenger side of the throttle body. One is for the ECU (green) and the other is for the gauge in your dash (grey or black usually).

Also what brand/model of ECT and where'd you get it? These trucks are absurdly sensitive to non-OEM electronics, it's general rule of thumb not to use.

Did you try swapping in the old ECT yet and see if it resolves?

 

Thanks for the early reply. Yes I replaced the one on the right as you are looking the engine from the front. I used Chilton Guide book. Got the part at Napa and they said it was OEM. I actually just replaced it today and test drove and the check engine takes a while then shows up after a stop usually. I may try to order one from Toyota. I’ll try to clean the old one and replace. It checked out okay with a continuity check but I didn’t check it in hot water. Thanks for the tip.

 

There's a process in the FSM to measure resistance across the temp sensor with a multimeter to confirm if it's operating properly.

Failure to enter closed loop can be caused by a few things. But I'd want to see what the actual temp is, so I'd probably hit it with a thermal gun...