[Eugine]

It was ok like two or three days ago, and it's just the regular horn instead of the siren, and yes I know how to toggle sirens, tried everything but didn't work, help please.

[Tomboeg]

I take it you are speaking of a police cruiser.

You can tab the capslock button quickly to toggle the siren on/off or hold the capslock for longer to sound the horn if your siren is off.
If the siren is already on, you will switch between a siren sound.

Are you using the emergency light mod by any chance?

It's also possible that the server you are playing on tempered with the sirens. As for the recent siren update.

[Eugine]

Yes I am using it.

[Tomboeg]

Then it is not client related. It's due to a certain setting in your ELM Config.
Uninstall ELM and eventually reinstall it. Double check your siren options in the config before installing.
This tempers with the siren.

[Eugine]

Well it just worked, but it rarely works when I slightly touch the horn button, sometimes you can't focus on how to press the button and it takes time to actually turn it on, dunno why it's not like before.

Also, uninstalled ELM and still same problem.

[Tomboeg]

Try switching on the frame limiter, this might help.
Keep in mind that you only need to tap it once, do not press it but simply tab it quickly. That should toggle.

If this really doesn't help you can try and delete your gta .set file.
Try to play around with your game settings and see if you gain any positive results.