unless you sink K&N with oil that splash like rain on MAF sensor

then it may cause what is worse than rough idle (super rough idle)

apply just enough oil , let it dry for day or two install and wish for the best of luck

 

Aftermarket intakes do not cause problems vs. the OEM. I installed an Airdoc intake 4 years ago.
I run a Spectre DRY filter. I have had ZERO issues with that setup.
As stated above, WET filters like the K&N can cause issues if overoiled.

I also choose not to deal with the hassle of maintaining an oiled filter.

 

I have run K&N (and some other brand oiled filters) in virtually everything. Never had a single issue. If one can follow the K&N recharger instructions, its pretty easy to re-oil after cleaning. Some peeps follow the old.... if some ____ is good, more must be better rule. Lord knows some folks can't change a light bulb?

An intake system crates ZERO issues by itself. Like I said on the first page, our OP's dealer (now I will also add the OP's "Mechanic") is/are full of crap. I would really like to hear their BS session of how an intake damages your engine. If you install it incorrectly and have a leak downstream from the MAF or at the MAF, you will get a CEL.

For H3s particularly, a lean bank code from a hypothetically correctly installed K&N Intake is an oxymoron.

Many, many K&N intakes (which also use K&N filter) have been associated with throwing a CEL for many different vehicles. I'm not going into details or bashing a forums sponsor here.... like my grandfather used to say.... If you don't have anything good to say, than keep your trap shut.

So here is what I have to say about K&N intakes: They make them for lots of vehicles and variations of vehicles.