I'm at the part with the It boss. I have absolutely no ammo, grenades, or any health boosting items.
I can't open the doors with my knife, obviously. Does anybody know a cheat or hint to get more ammo, other then buying a gun, as I have no money in game.
Wow! How did you do that?! I played RE4 on PS2 several times on hard and never managed to get low on ammo (healing not counting).
As for cheats, I'm afraid there are none.
Maybe some general tips might help you on another walkthrough (no harm meant!*):
- learn to embrace your toothpick of ultra-destruction! It takes care of boxes&co (you sure know that, but it's always worth mentioning), it teams perfectly with enemies on the ground, staring/ climbing through windows/ up ladders and it even allows us to go all offensive, once we recognize the patterns of our foes.
- exploit the environment. This goes of course alongside with the use of knive, as it is perfectly safe to crowd-controll hordes to follow you to a ladder and finish them of without ever firing a single shot. The same works with kicking doors open, once you sense enemies right in front of it. RE4 emphasises this nicely.
- go back sometimes to "farm" earlier visited spots. Enemies respawn as well as chicken, so with a little (yeah, sure...

) patience, you can collect ammo, healing items and money. Best to try the farm, but honestly I never tried myself.
- aim for their heads. Seriously, Leon sure took a few levels in bad ass (Chuck Norris) once he learned that roundhouse kick. Spot a group, aim for the nearest head to make him tumble, run up and kick the hell out of him and his friends! To add even more injury to injury, knive them when they can't defend. And don't be afraid of symbionts: these will appear regardless of headshots, so no need to restrain yourself.
- let the hunters be hunted. Meaning: go for the chainsaw guys as they mean money and money means more upgrades and we all know what that means
- be sure to finish the shooting ranges. Money is always okay and you get some extra shooting practice at the same time
As for the weapons of choice (mine of course

):
- the standard handgun, I
love the 5x chance for critical headshots
- the striker, once it's availlable. I only upgrade the first shotgun if I feel the need for 8 extra buckshots once.
- the second sniperrifle (sorry, been a while since I played last time) as it has not to be reloaded every shot.
- broken butterfly. 50
Dmg. Questions?
- all types of grenades. Once you get the usage, they can really be lifesavers. Especially love to use incinerates while on the statues' hands
- rocket launcher for those pesky bosses. I know, I know, it's not great, but some of them just suck! Will train more, promised.
* Don't want to confuse anyone, but had some situations, when people got angry about that. Peace