wfo9
New member
Surprised catch are being put on these vehicles...based off my experience they did nothing whatsoever to reduce carbon build up. Coming from a GTI which are notorious for early carbon build up, it was proven the catch can did little to nothing to reduce build up. Same results for both mine 2013 TFSI and my buddies 09 TFSI. What would be so different on the 4runner especially with no forced induction?
Carbon build-up can just be part of fueling and have nothing to do with the oil from the PCV. The main purpose of the oil catch can is to improve effective octane and keep the intake clean. It can't possibly catch it all...
From my experience.. the combustion chamber is never a big problem (on port injected motors) from the PCV. The fuel washes it right out and keeps it nice and clean. The problem is the intake and runners. They gum up. Also, once you get on the gas after lots of build up. The oil pushes down and there goes your effective octane and it detonates. Knock sensors pickup it up and keep the motor together, but power goes to crap.
These cans can't prevent all the oil. But every bit helps IMHO.
On direct injection motors. they do have problems with buildup from the PCV and it can be very expensive to clean up.
Here are some pictures of my 5th gen intake runners when I took my manifold off at about 70k (before I cleaned it). The truck had 45k on it when I got it and I put the catch can on at about 55k. It was pretty nasty and it appeared that most of the buildup was very old.
The ports after the injector were not bad and the chambers and pistons were nice and clean. But the intake runners were nasty. It cleaned up easy, but the consistency was like a partially dried glue.
Last edited: