Changed radiator now check engine is on...

[fattiplat]

Okay so I installed my new radiator from mishimoto. I didn't disconnect the negative and I also installed a new thermostat that opens 62deg. Well after plugging everything we disconnected and filling up the radiator I take it for a spin. I come back no problem. I turn off the vehicle and then turn it back on and check engine comes on. I refill the radiator again no changes. So next day i take it to autozone for them to pull the code. Comes up my coolant temp sensor and my knock sensor is setting it off. Well I take it over to friends shop and he resets it, believing its just because we didnt disconnect the negative. Well i take it for a long drive and it is all good. I come back to the shop turn off the car and talk with him. As soon as I get in and drive again the light comes back on. Well now I get home and notice one of the plugs near where the radiator hose connects to the top of the engine is not connected, so I plug it in. I don't expect it to shut the check engine light off. But I would like to know what possibly could be the cause, and how come the knock sensor went off like that? Is it a simple fix? And if now I plugged that one back in if i clear it will it change anything? Help please?

[blacksrjdm]

Reset the code and see if it comes back, that is the only thing to do. That will answer your question....

Obviously, the sensor that was unplugged was the coolant temp sensor if the CEL kept getting set. Knock sensor is a dummy code. Want to know more about the knock sensor, search knock sensor. Want to know more about the Coolant temp sensor, search coolant temp sensor.

It would be however common sense that if you have a check engine light on and you scan it, comes back coolant temp sensor, and there is a random sensor unplugged, that is probably the issue.

[fattiplat]

yeah i figured the same thing as common sense would say I just wanted to see if some else had other ideas. Well thanks man appreciate it.

[godofspeed666]

First thing Nissans are none to have a notorious knock sensor code. It will store the code in history but not set off the light.

And you probably had a coolant temp sensor unplugged.

Let me know if it comes back on.

[fattiplat]

yup sure was.. took it back to the shop and my buddy cleared it out and it hasn't came back on. Now that has got me thinking that, that is weird how it had the knock sensor malfunction thing...