Pixel 3a is already running smoothly on delivery, but installing a custom kernel can make your experience even better. With the ElementalX kernel, you can take advantage of a host of new features, from finely-tuned CPU optimizations to boost performance or battery life, to adjusting display colors for your screen.
Most likely use the TWRP recovery environment to install a custom kernel, but it is currently unavailable for Pixel 3a. The developers are working on it and will release it when the time comes to make sure all features are working and stable. Until then, I'll tell you two alternative methods that you can use to install the ElementalX kernel.
Please make sure you meet the above requirements for the method that you use to apply the ElementalX Kernel to install on your Pixel 3a. Click on the links and follow the instructions to meet the requirements for the method of your choice. When done, continue with the rest of the instructions below.
This method requires a little more effort, but allows you to do so in control of the process all the time. It's perfect for anyone who prefers the "do it yourself" mentality over the automated method with the second method below. It can also be a great learning experience for those who have never manually flashed a kernel before.
Before you can start installing the kernel, you must download the main image file itself using the following link with a computer.
The latest version of ElementalX for Pixel 3a at the time of this manual is 1.02.
Now you need to move the "exkernel" image file downloaded from the previous step to the platform-tools folder on your computer, which is used to send ADB and fastboot commands to your phone. You will find the folder platform-tools in your ADB installation directory. However, if you need further assistance, read our guide.
Step 3: Booting in Fastboot Mode
Long press the power button and select the "Power Off" option to completely turn off the phone. After shutting down, simultaneously press and hold the power key and the volume key until the Fastboot Mode menu is displayed. Connect your phone to your computer with a USB cable and leave the phone as it is for the next step.
You should continue to sit in your phone in fastboot mode and be ready To set up your command-window environment for Fastboot. Opening the command window in the platform-tools folder allows your computer to execute the command required to install the kernel file on your phone. If necessary, access the following link to make all settings before proceeding to the next step.
Step 5: Install the ElementalX Kernel  When a command window is opened in the platform-tools folder, it's time to finalize the kernel file to your phone to install on the system partition. Enter the following command and press Enter.
fastboot flash boot exkernel.img
fastboot flash boot exkernel.img
Note: Mac, Linux, and Windows PowerShell users will most likely need to add a period and a slash before entering any of the fastboot commands (eg ./fastboot flash boot exkernel .img).
Once the file installation is complete, you can restart the phone with the following command and then press Enter.
fastboot reboot  From this point on your phone should be restarted as usual. This is exactly what you want.
Lastly, you need to check your kernel version to make sure that you are really using ElementalX Kernel installed on your system. After restarting the phone, go to System Preferences and follow the path below to check the installed kernel version.
Settings -> About the phone -> Android version -> Kernel version
It should see something like "ElementalX-P3a-1.02" in the kernel section if everything went well during the installation process. Alright!
This method is obviously the simplest, as only a few steps are required to complete the tips , However, you will need to purchase flar2's EX Kernel Manager app in the Play Store to use the feature to automatically update / install the ElementalX kernel. However, if you intend to optimize and modify your device in the near future, the purchase is well worth it.
Before You Begin to Install the ElementalX Kernel Automatically on Your Device You need to download the official EX Kernel Manager app from flar2 through the Play Store. Click the following link to install or buy the app as needed.
Once you open the EX Kernel Manager app for the first time, you need to install it may grant superuser access before you can get started. At the Superuser Request prompt that appears, tap Grant and you'll immediately get the appropriate root privileges.
Once the permissions have been granted, you should be in the app's main menu. All you have to do now is to tap on the device section below where your current kernel information is displayed, and then tap the large "Update Available" button. When the download and installation screen appears, leave it in "Express" mode, then tap the "Download" button.
When the kernel download is complete, tap "Flash" on the screen that appears to start the automation installation process. After a few seconds, the kernel installation on your system will complete, and you can tap Restart to finish the process once and for all.
If your phone is after Restarted, re-launch the EX Kernel Manager app to make sure it appears to you have the ElementalX kernel installed. You should see something like "ElementalX-P3a-1.02" in the kernel section on the main screen if everything went well during the installation process. Alright!