Hello, I'm Danny.
It's possible you have an injector or injectors that are stuck open causing raw fuel to be unburned and leaking into the exhaust system from your truck from running so rich. Here is a tutorial showing how to change fuel injectors:
https://www.2carpros.com/articles/how-to-replace-a-fuel-injector
I've attached picture steps below on how to remove and replace the fuel rail to gain access to the fuel injectors on your truck. Hope this helps and thanks for using 2CarPros.
Images (Click to enlarge)
May 29, 2021 at 10:53 AM