Ford gearbox

Hello friends I have a Ford Aerostar of 88 3.0 V6 with automatic transmission, it still works very well, but I want to know which manual transmission it fells to think about changing it.
In addition, it is a little slowly slowly when climbing some slope and spends more fuel from the account.
I regularly use injector cleaners, will it be dirty injection or damaged escape sensor ????

Let's see if anyone can help me with this important issue, thanks from Costa Rica.

What type of injection cleansing do you use?, depending on this, your probe Lamda is working badly or out of range.

I have used Wyns injector cleaner and penzoil also injection cleaner.

Are they one of the linpiers that made in the pond?

If friends are one of those who dissolve in the fuel.