ZForce

I was going to share this same experience last summer in dry weather when I was experiencing this and then again when it rained but discovered through alot of testing that it only occured under certain circumstances.

1) When the car is parked at at angle, as when the nose of the car is on an upward angle. For instance when washing the car on an inclined driveway.

2) Parking in the rain in a parking stall that places the front nose on an upward angle.

Ever since then I now wash the car in the street on a flat surface. As far as the rain getting into the engine bay and dripping down on the top of the filters was another issue. As I cannot always get a flat surface to park on when it rains.

As it turned out water was entering the hood/engine bay and running down to the tops of the air filters. I even tried to block those areas in the engine bay that have gapping holes fron the inner wheel well. I found that Injen when manufaturing their CAI that they were lucky that Nissan has a 1" in diamter hole cut in the under cover that is exactly positioned to flow air to the inside of the air filters. I plugged the hole with a rubber plug and covered up the gapping hole in the fender well only to discover the air flow and car was gasping for air. All of it was removed and back to square one as to why water only messed with the MAF when the car was parked in the rain or after a wash on my inclined driveway. The car did not get any water on the filter and MAF when its moving only when parked and water is running down the hood.

Turns out Nissan did not do a good job manufacturing the gutters on the inside hood and fender. Then again they did not intend for the stock air box to be removed either. When the car is parked at an upward angle and water from washing the car or rain will seep downthese channels on the fender and make its way to the air filter causing the MAF to either cough very bad or worse put the car into limp mode.

Solution was to take some black weather insulation with adhesive backing (home depot) and run it along the edge of the fender halfway down from the top of the head lamp to bottom of headlamp.

Fixed!

Sorry for the long winded but this bugged the crap out of me when it first occured after my install of the CAI and summer came along and washing the car in the (inclined) driveway. After the fix I got lazy and really thought it was just mine and the bro's Z and no one else was having this problem, maybe because they never wash their car on an inclined driveway or park their car on an inclined parking stall in the rain to have this happen.

Glad I am not the only one having this issue. Btw I still have no regrets buying Injen as I still did not have to cut into my car to get the G3's to fit and accessing the air filters to clean (thru the inner wheel well) is alot easier than removing the bumper. Hope this helps.

For those wanting to pick up some of the filter booties, I ordered some from Amazon and they double shipped me for two cars, so I have extras that I am willing to unload at a good price.