I wish I Knew EARLIER! Post Cat Oxygen Sensors | BMW E90 DIY

In this video I show you how to replace your secondary or post cat oxygen sensors on your N54 powered BMW. I am working on my 2008 BMW 335i. This video shows you how to save some money by using universal Bosch sensors instead of paying the premium of sensors made for the car. The head of the sensor is the same and it is OEM quality. We get into some theory as to why they are important on modern direct injection cars and discuss how they can improve how your car runs. They are not just to sense if your catalytic converters are healthy. You can purchase the sensors here (affiliate): https://amzn.to/306Vq6f I know I neglected them thinking they weren't important but learned how valuable healthy secondary oxygen sensors can be for your car. Consider replacing them if they have a lot of miles on them, even if you're running down pipes. Thanks for watching! When you see the word "affiliate" listed beside any link in my description please know that this is a custom link and I will earn a small commission if you opt to purchase using said link. This is at no extra cost to you so it's a win all around :) Thank you!