I have a 200 accord ex with a 2.4 v tech engine.

I keep smelling antifreeze after shutting the car.
I would like to change maybe the thermostate and the antifreeze fluid, it seems to me that you should only change the fluid from honda products is this true.

please respond

When you smell it after shutdown, usually means it's seeping out onto something fairly hot....look at hose connections close to the motor and seams where radiator tanks join the core.

Changing thermostat and coolant isn't going to solve anything unless it runs hot. You have to find the source of the leak.

Honda uses standard extended life coolant as far as I know.