I now have 50K Miles on my truck! I decided to add a Mallet SC kit. After removing the intake, I checked the intake valves and expect to clean them up given all the talk about the deposits that collect on the valves. So here are pics of what I found. These are in sequence from Dr-Side front to back and then Pas-Side front to back. Only 10 images can be loaded, but 11 and 12 look really similar to 5/6 from the driver side. Seems the deposits are heavier on the valves toward the rear of the motor. I can imagine at 100K miles i'll have quite a bit of deposits on the back of the valves. However, i'm not clear on how the catch can can prevent this. From what i've read this is a result of reversion from the combustion chamber and oil that seeps past the valve guide seals. I do run premium fuel and synthetic oil (at least thats what the dealer tells me the use). I'm also in Tampa FL where the weather is warm mostly. Would running in the colder northern climates create more contaminants to form in the oil? I have decided to clean the valves anyhow with crushed walnut route so I'll have a fresh start. I did ask Mallet, who put together a pretty high quality kit, and they don't include a catch can or recommend you should install one. I'm not arguing the fact catch can's pull oil and contaminants out of the PCV system, but of all the videos i've seen of cars getting a valve cleaning that "are" running a catch can, they still have build up on the back of the valves. So is the catch can just really a solution to keep excessive oil out of the intake? Anyhow, just thought i would post an update from my last post at 15K miles when there was only a slight amount of stuff on the valves.