Is it worth to invest on? Does it really increase HP? By how much? Good for the car?

 

To me it's worth the investment. You must be careful when using such filters tho, to avoid over oiling the filter medium. This may excessively coat the MAF sensor and cause faulty readings and a poorly running engine, and ultimately requiring a replacement MAF sensor.

This filter doesn't add h/p, but rather allows the engine to develope full horsepower potential by allowing maximum airflow to the intake.

A good mod, and well worth $40.

 

wow...is it hard to add oil and install the thing??

 

No and No.

First No... You don't have to spend $40 if you buy your air filter from Grubbs

Second No... It's not hard to add oil and install the thing. There are DIY's all over the net and cleaning/re-oiling is as easy as following the instructions provided in the K&N cleaning and re-oiling box.

 

how can you tell if you have too much oil on the filter?
I have reoiled mine.. I dont see any excess oil dripping.. but I'm still worried id I the filter as too much oil.. I dont want to mess my MAF sensor

 

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I believe it was Neffster who first brought this up, and his suggestion was to clean and oil the filter as per the instructions, then, to be sure you don't over oil, place the filter application side down on newspaper overnight to soak up any excess.
I've done this too, and you soon learn just how much to put on so as not to waste any or have the excess cause any problems with the MAF sensor.