K&N cold air intake
 

I bought and installed a K&N cold air intake. Installation was smooth and easy. However, I am having some second thoughts. I have read some complaints about mass air flow sensors failing with the K&N and issues with water getting to the engine through the filter. K&N says that it is both impossible and ridiculousis for the mass air flow sensor to fail with their systems. They dont say anything about the water issue. I had a mechanic tell me to reinstall the factory system asap. Does anyone have any advise?

I doubt you are still looking for reply but for others, there is a K&N Filter Wrap that will assist with making the filter water repellent. Not water proof but will help if your concerned about sucking up water if driving in the rain or wet areas.

You may have problems if get overenthusiastic when it comes time to clean and re-oil the filter. Excessive oil can get sucked in and foul the MAF. As for sucking water in, it can happen regardless of filter if you drive in a deep enough puddle. This could cause all sorts of electrical problems, and in the worst case enough water could get into the cylinders and cause hydro lock and a broken engine.