Is there a cheat code that does not use action replay for wild shiny Pokemon in pearl version without an code?

Yes, there is a way to obtain shiny Pokémon in Pokémon Pearl without using an action replay or any sort of cheating device. This method is called Masuda Method.

What is the Masuda Method?

- The Masuda Method is a technique in Pokemon Breeding which increases the possibility of obtaining a shiny (different coloured) pokemon

How does it work?

- Obtain 2 pokemon from different language/ region version games

- Breed these two Pokemon by putting them to the Pokemon Day Care

If these conditions are met a Pokemon's chance of being hatched shiny increases from 1/8192 to 1/683.