The PlayStation 3 modding scene remains active, but Sony’s 4.89 firmware update introduced specific hurdles for those looking to revert to older versions or install Custom Firmware (CFW). If you are looking to downgrade from 4.89 to 4.88, the process is not as simple as clicking "undo." It requires specific hardware compatibility and software exploits. Can You Downgrade Any PS3? No. Before starting, you must identify your console type. Most are downgradeable.
Since you are on 4.89, you cannot simply install a 4.88 update file over it; the PS3 will block it as an "older version." You must exploit the system memory (Flash) to allow the installation of older or custom software. how to downgrade ps3 firmware 4.89 to 4.88
If the power cuts during the Flash Memory Patching (Step 2), your PS3 will become a "brick" (unfixable). The PlayStation 3 modding scene remains active, but
Always verify the MD5 hash of your firmware files to ensure they aren't corrupted before installing. Since you are on 4
Doing this removes your ability to run homebrew apps. ⚠️ Essential Safety Tips
You can then take an official 4.88 update file and install it over the CFW.