Recently installed the Airaid 200-985 Modular Intake tube and a JLT Performance catch can. My truck is a 2019 5.3L LD. I am posting here because it is pretty much identical to the 2018. The 2019 mods forum is all about the new body style and engine bay.
For the record I did not install the intake tube because I expected big gains in power or mileage, but because I like the way it looks and sounds. Installed one on my 2010 4.8L and really liked it. I did enjoy seeing a dyno test on American Trucks YouTube channel which showed a 28 hp gain between 3-3500 rpm.
The tube is a piece of cake (POC) to install and comes with factory OEM type connectors where the hoses connect to the valve covers. BTW the hoses are pre-cut so POC.
I installed a catch can because it seems like a good idea. I read all the pros and cons and looked at several manufacturers. I chose the JLT catch can because I like where it mounts, the mounting hardware, and that it comes with pre-cut hoses and OEM style fittings where hoses connect to the engine. The fittings at the can are installed by JLT. Lastly, I like the way it looks. Takes minutes to install.
I have not checked the catch can yet as have only had it installed about 1500 miles. As far as the intake, it seems to have more power when accelerating. Might be all in my head, but hey, perception is reality! I drive on the interstate a lot and for distances of several 100 miles at a clip. I have 12K on the truck and have never gotten the average fuel use reading below 20.2 mpg. After the intake install it went to 20.3 on the first interstate trip. Not much but it certainly does not get less mileage.
I highly recommend the Airaid 200-985 intake and the JLT Catch can 3085D.
Selo