Senobi

I always thought a K&N air filter was a good investment, You buy it once and there is no need to replace it and you gain a slight increase in air flow to the engine.

So I was reading past posts and found some information that said K&N filters are actually bad for the engine as they allow more dirt to pass through. Although there were other posts stating there is no issue So, I would like to ask, Is a K&N air filter a bad idea and if so, what do you have in your Q ?

uberwgn

This:

And don't overlook the fact the K&N "filter" is nicknamed the MAF sensor Assassin!

tenspeed

It depends on the definition of "bad". Any filter that increases air flow either has more surface area or larger openings.

The K&N filters allow more air to pass and they are washable. Your engine my not perform any better because the throttle body is usually the smallest passage in the intake system.

The down side is that more dirt makes it way through and if the filter is over oiled, the Mass Air Flow (MAF) sensor can become contaminated.

One way to see if your car performs any better with a less restrictive intake is to make timed 0-60MPH runs with and without a filter.

iNfiNkC

ive had a k&n in my car for years, just make sure its not dripping with oil when you first put it in.