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1hz Catch can or not?

Esben Bøll

New Member
Mar 4, 2020
Country Flag
I have a catch can installed....but should I uninstall?

If the catch can a good idea on the 1HZ?

Does it create unnecessary pressure in the engine?

From what I have seen reported by others, the answer to your last question appears to be ‘possibly‘, depending on how much restriction there is in your catch can. You can test if there is any pressure by undoing the oil filler cap so that it is only sitting on top and see if it is being pushed up by pressure. I believe the cans that use simple metal wool or similar as the filter do not increase pressure but those with proper filters do. The latter are only really meant for modern diesel engines.
I would leave it in and clean it with every oil filter change

Hi, a bit late in the game, but I'm new around these parts...

From what I know, a catch can (CC) is superfluous on a stock 1HZ engine. The oil vapours will harmlesly pass the intake manifold and burn as they should. Nothing to clog up.
If you would have an aftermarket turbo installed, especially with an intercooler, and/or an aftermarket EGR valve, things would get different, however. In this case the oily muck would settle in all manner of unwanted places and end up ruining your day. (E.g., I have an aftermarket EGR valve installed (needed for registration in Germany, before my time), and that might end up giving me trouble somewhere down the line. ...but I will be blocking & disconnecting the darn thing someday soon...).
Pressure issues caused by the CC seem a bit far fetched to me, logic-wise. After all, the inlet system simply does not need the pressure from the blown-by oil vapours, and that will constitute only a little fraction of the intake pressure anyway. So leaving it in place should cause no harm other than the need for a little maintenance every now&again.

Make sense to you?
Personally I would have a 1HZ exactly as it came out of the factory. If Toyota didn't think it was necessary then it isn't necessary, and can only serve to potentially reduce the legendary reliability of such a great engine.