Just got an '04 and air filter is black with oil. Going to replace with a green or K&N (using stock CAI box). Looked at mazdaparts and see the greddy catch can for $100. Do I want 15mm or 9mm, and is there a cheaper one out there? I don't need shiny steel or chrome, just reliable function.

Also, if I don't install a catch can, will the oil dripping on a K&N hinder it's performance more than a standard filter, or can I just use no catch can and clean out the K&N more often?

 

Is your car NA or FI

 

If you have oil in your intake that often, you really do need a catch can.
The oil can mess with your MAF sensor, make the throttle body flap sluggish, and worst case would be oil in your intake manifold where it can seize the SSV valve and prevent it from opening.

 

It's NA. When I took the filter out to look at it, I cleaned the MAF which was really bad and also the throttle body valve which actually wasn't too bad. I haven't looked too much into the upper manifold yet, is it a huge pain in the *** to disassemble to clean the SSV valve? Will running seafoam through the manifold following the Mazda's decarb process clean out the SSV?

 

No... when you use the cleaner through the maintenance ports on the intake manifold, you are actually spraying into the primary runner.
You will not reach the SSV through there.
If the throttle body flap wasn't that bad I probably wouldn't worry about it.
When I cleaned a SSV, I actually knew I had to because I reached a finger through the throttle body valve and had oil all over my finger (inside the upper intake manifold).

 

I'm not familiar with the SSV, I just googled it, but I don't yet have a Haynes for my 8. Is the SSV after the EGR?

 

This should help:


The SSV (Secondary Shutter Valve) opens at 3250rpm to allow airflow through a secondary passage.

Like I said, cleaning the SSV would be worst case and I've only dealt with it once.
A local took his car in for an oil change and they either overfilled it or didn't use a funnel.
Not using a funnel can allow the oil to run down the oil filler neck and potential into the breather hose that connects to the intake, the funnel sticks down below the breather hose.
So unless you are curious to take stuff apart, I wouldn't bother unless you really think oil is in the intake manifold.

 

Thanks Jon316G. I'll leave the SSV be unless I have other needs that necessitate access. I'll probably install the oil catch can; it doesn't void warranty does it?

 

A catch-can *shouldn't* void the warranty... but dealers will blame the strangest things sometimes.

 

Its an 04 so don't worry about warrenty.

SAve 100 bucks. Get filte, put on end of oil fillere. Cap off intake tube.

No more problems.

 

someone used a BudLight aluminum 16oz bottle as a catch can but I can't find the thread! that would b cheaper than 100 bucks and you could have some spares

 

Well that's a simple solution.
Why is the overflow routed to the intake anyhow, just to relieve oil pressure if overfilled?

Why not worry about the warranty? The part of the warranty that I'm concerned with is the 8 year/100k mile warranty on the rotary core. I don't want the dealership to deny me a new engine because of a modification.