Wet mass air flow sensor

I recently made a 2 hour trip up in the mountains with my truck and on the way back it was pouring rain the whole ride home I have a Urd cold air intake the engine would jump up and down in the 3-4K rpm range and the check engine light flashed on with p0330 code I think the mass airflow sensor got soaked. The sensor Is 3 inches away from the cone. It drives normal in low rpms and it really rough at idle.

 

Common problem with the URD air intake. You may have to rig up a secondary filter somehow. Maybe a sock of some sort to go over the URD filter to add an additional layer?

 

Put the OE assembly back on and feel free to drive in the rain?

 

this is the reason I went with a trd intake. the urd isn't meant for wet weather. put a snorkel on it

 

Urd has an optional hydrophobic sock.
This does effect performance, ymmv.

The splash shield wont do much on its own.

Either ur pulling water past the filtet and its hitting the maf sensor (merging onto freeway in the rain can be a pita). Ive had the truck go from 3k rpm or so,to stumbling when water droplets hit the hot wire.

Also, mine had a gap at the maf sensor seat when i screwed it down. This was using the factory harness that i extended via the older urd kit. The maf seat woukd interfere with the harness where it gets larger at the end. I could either clip the harness in 1st, and then snug the maf sensor to the intake and have it at an angle (not a good seal)..... or mount the maf sensor snug, and not be able to clip the harness all the way (no click).

This was about 2yrs ago.... maybe things have changed, but u may wanna check the maf sensor seat. Do u get a high pitch whistle at certain rpm? Say around 1500 to 2000rpm?
That may be the maf seat issue, as mine whistled.... which makes an inlet for rain, and possibly unmetered air.

 

Is was in the the 1500-2000 rom range 90% of the drive home. I did not hear a high pitch whistle because I had music going however when I would accelerate past 3500 rpm the engine would stumble before climbing the rpm range. Could it be possible that driving they much time in hardcore rain soaked up the cone and every time I would accelerate it would pull water over the wire on the maf?

 

I suppose its possible.
Dry it and test.

 

I checked the seating on the sensor it looks good but around the outside of sensor is wet. I test drove it a little while ago it seems to be climbing the rpm ranges better then it did when I was driving back from the trip but still has a minor sputter. It's raining here still so I'll have to wait until the rain stops to fully dry out and check the sensor and maybe clean it with electronic maf cleaner. We don't really get bad rain storms here in Sacramento.

 

Old thread, but figured I would comment with my recent experience. My URD CAI is doing the exact same thing. I have a hydra shield on the filter. It probably helps, but the intake is definitely pulling in water. It only happens at higher speeds in really heavy rain. It's happened twice now. I have hptuner logs of the maf and afr being erratic. The knock feedback actually started showing signs of increased knock. In my opinion, the issue isn't the small amount of water entering the cylinder, it's the erratic behavior it causes with the maf sensor. Then it domino's into fueling, knocking.
I really like the intake, but it does pull in water during high speed, heavy rain conditions, especially with a SC. At first I thought the maf connector could be getting water in it. I cleaned it, verified the seal, installed dielectric grease, and made a protective cover for it. I feel confident it's not the connector. Just sharing my experience, maybe it will help someone.