N249 & N80 delete in 2025..

[cwfao]

Have got a catch can kit from Sep auto, instructions say to remove all lines to and from n249 and n80 valves. Cap all lines, but leave both fuel evap lines either side of engine bay venting.
Looked through all the forums but none that are less than 11 years old, no real updates on whether it’s good or bad.
If how I have it now.. do the valves need coding out and how i’ve got it set up now should work?
Thanks in advance!

[RMode]

They both need to be coded out

Is it good? Depends on your definition of good tbh. You’ll smell fuel with a catch can that’s vented to atmosphere for one.

I’d say 90% of the S4’s that run vent to atmosphere catch cans have zero need for them, and it makes things worse (especially if it’s cold out) than better.


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[CELison]

You don’t need a catch can. A good stock PCV system is fine unless you have some wild setup.

[cwfao]

I will get them both coded out, deleting them shouldn’t mess with the tune?
As for blocking off lines, is it correct to leave the 2 evap lines venting but block everything else off.

[cwfao]

It was more to clean up the mess in there, much cleaner just 3 hoses to a can then all the crap before.
Old pcv system was in pretty bad shape, not sure if the valves are even working.

[Silverex]

It was more to clean up the mess in there, much cleaner just 3 hoses to a can then all the crap before.
Old pcv system was in pretty bad shape, not sure if the valves are even working.

Definitely won’t be cleaner adding way larger lines and a big ass can in the bay.

A new spider hose is the way to go for most setups.

[CELison]

I would keep the n249 too.

[KiwiRider]

Can someone please explain why leaving the two evap lines into the inlets shouldn't be capped? Seems wrong, don't want to introduce more air post-MAF as it will mess with what the ECU is seeing no?

[CELison]

They have to be capped if you’re not using them. Personally, I wouldn’t do any of this for a catch can. The stock PCV system is the way to go and is less clutter than a bulky catch can Medina re-sold you from EBay with some heater hose.

[ZeroGrav]

Just got the can setup too, it's definitely a budget setup, after receiving and getting my eyes on it, I've decided to just buy a 034 spider hose setup instead. Everything still works and I prefer to keep the car less "race car" like

[RMode]

Just got the can setup too, it's definitely a budget setup, after receiving and getting my eyes on it, I've decided to just buy a 034 spider hose setup instead. Everything still works and I prefer to keep the car less "race car" like

Just get a stock one tbh. Or even the project b5 one which is simple but works fine.

Nothing seems to be resold more than sep stuff, often from new.


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[CELison]

You can rebuilt your stock PCV system with heater hose for $10. Just reuse all the fittings and whatnot.