For Honda the ECT does not matter if the polarity is reversed.

why is it when im in 3rd gear it drags and sometimes check engine appears?

What is the trouble code for the MIL indicating?

19 and 6

Sorry for the delay in replying. The email notification is not working correctly so I am not aware of you replting untill I check through the posts.

I have the diagnostic procedures here, hope they are helpful.

The 2 wire connectors are rather close to each other, ensure the wire color are correct for each sensor as they could be mixed up if the harness wires had lost their connectors and/or insulation.

my solenoids also has leak

The lock-up solenoids? That can result in the Code 19. If the leaks is from gasket it should not trigger the code but if from the solenoid body, yes.

can i spray carb cleaner inside throttle when i remove iat sensor?

Yes.

Here is a guide to help you

https://www.2carpros.com/articles/how-to-replace-an-idle-speed-control-motor-iac

Please let us know what happens.

Cheers