None of this trainers works.
I searched everywhere for a Resident Evil 4 trainer but couldnt find 1 that really works.
The solution was to use the program "Cheat Engine".
With it i got unlimited health, noclip ammo, freeze timer on the mercenarie game, etc...
Its a little annoying to use it but it´s worth it.
You can downlaod it on www.cheatengine.org/
Or just google it.
There´s a tutorial on the program´s help.
You will search for the numeric values of each data you want to modify in the game.
Start the game and the Cheat Engine.
Equip a Shotgun (full on ammo) and "ALT+TAB" to the cheat engine.
Search for a "Unknown initial value" "4 bytes" value tipe.
It will find some millions of numbers.
Return to the game, shoot once and "ALT+TAB" to the cheat engine again.
This time, search for a "Decreased Value" and click next scan once.
It´ll narrow the search for less numbers (but still many).
Keep doing this procedure until the search is narrowed to around 10 cases.
Choose one of the lists numbers, and freeze it.
Go back to the game and shoot, if the ammo counter is changed, u chose the wrong address on cheat engine, go back, delete that number and pick another, freeze it and go back to the game again. Some of those numbers control the ammount of ammo your gun have.
If u freeze it, u will have a No-Clip cheat for the ammo.
That works with anything on the game.
Tip: once u have the number, unfreeze it, load the weapon to it maximun capacity and copy that number on a txt document for a future use:
Next time u load the game, the number is the same, but it´s address changes, all you have to do is on your first scan, u do a "exact value" search with that number, it´ll find few numbers (3 to 20 tops), then, u go back to the game, shoot, and search again for a decreased number, it´ll show only one, gets much easier every time.
All guns have different numbers and adresses, so you´ll have to do it with every one u want a no-clip cheat and your life.
The good thing is u have more trouble only on the first time searching.
Remember to unfreeze the numbers when upgrading the weapons and when u do it, the numbers change for a higher on, so copy it on your txt document every change u make on the game (incriesing health also) for a future easy search.
It´s a lot of woork, but it was the only way i found to cheat on this game.
The good thing is: this works on any game you ever want.
Sorry for my english, its a little bit rusty.
Hope i helped!!!