Just re-check everything.

It could be a simple as the fact that "after cleaning" there is now more/better air flow thru the filter and that is what you are hearing???? People put "hot air" or "short ram intakes" on cars all the time and get a different sound, I admit I'm guessing here.

In the end, I would not worry too much about the sound.

As stated, my worry/concern is the MAF - you had oil in the "bottom" section so I'm worried what might have come off the top side going to the MAF and intake. Pull the top of the air cleaner and look for signs of oil on it - if it is there, I'd plan on a cleaning of the MAF somewhere in your future. I don't think it is something you need to stress or worry about right away but for me to sleep better I would plan on a proper cleaning just to be sure.....knowing my luck it would show up in six/seven months when it is cold a heck outside....I don't function very well when temps are under ~50F, I know, I'm a whimp.

 

That's exactly what I'll do. I assumed it was better filtration, I just hoped it wasn't WORSE filtration because of the excess oil. I doubt that now, though. I had a short ram in my car and hated it anyways. Who wants a Honda that sounds like a muscle car?

Gotcha, I'll check that out soon. No worries, cleaning it won't be too hard. Thanks for the help.

 

You are supposed to go 50k miles before cleaning, per the K&N site.
K&N Air Filter Cleaning Instructions

 

Yeah I know, that's why I'm so concerned. I thought it was 10,000 miles.

 

UPDATE:

I think the problem is basically fixed. First off, I definitely over-oiled the filter. Apparently my filter only requires 0.81 oz of oil; I must have put in at least 2.5/3 ounces of oil. Lesson learned for next time. Luckily, I wont have to re-oil it for another 45000 miles.

The loudness of the filter has been fixed. I simply took out the filter, cleaned out all the excess oil and really tightened the two bolts that hold the air box in place. After that, it sounds like normal again. My concern definitely wasn't for nothing since now everything sounds and feels like it was pre-excess oiling.

I also don't think the MAF sensor got any oil sucked into it. Most of the oil dripped downward and out of the car. I have two final questions:

How do I know that my sensor is fine? Everything looks, sounds, and feels fine. I haven't had anything out of the ordinary happen. It's most likely fine, but it definitely was a close call.

And finally, why does my air box have room in the back for my to stick my pinky finger in and touch the filter? What I'm trying to say is why is it slightly open in the back? Everything is sitting flush, there's no cracks, and everything is tight. Why are there numerous openings in the air box?

Thanks for all the help guys, besides my two curiosities listed above, everything is good.

 

Certainly doesn't seem normal that you can touch the filter. Is that upstream or downstream of the filter element? If it's downstream that's absolutely not good because it can suck unfiltered air in through that opening.

Maybe it's a hose or a plug that's missing??

As far as the sensor, if it was damaged it should throw a CEL.

 

I've seen oiled MAFs which took a while for the oil and collected dirt to harden around the MAF before the CEL would be thrown.

 

You lost me. I have no idea what upstream or downstream means. If it helps, I'll try to explain it a little better. When you pop the hood open and touch the air box, on the back of the air box and behind it where the clip-on part of the box meets the bolted on part (when you undo the 3 clips and the top of the air box pops open, that's what I mean by the clip-on part), that's where there is a tiny opening. The top part is sitting flush and even after pushing down very hard on the air box it still doesn't close the gap completely. Everything is as tight as can be and is in the proper position. Besides putting the drop-in filter in and taking the air box out of the car one time, the air box hasn't been tampered with and all hoses are there. I originally had a short-ram intake that I hated (for about a month or so) and returned which is why the factory intake was taken out in the first place.

What's a thrown CEL?

 

Unfiltered air comes in the bottom of the lower (bolt-on) part of the box. Flows upwards through the filter & clean air is above the filter. If you can reach into the box & touch the top of the filter, that means unfiltered air can get in through that same hole.

The clips are to the front of the box, while at the back there's some kinda hooks that you have to put together like a hinge of sorts. If those hooks aren't together properly at the back, maybe that's the opening??

 

If you can touch the filter, you've didn't install the cover back on correctly. There are two guides on the air cleaning housing cover that have to slide into two slots before you engage the metal housing clips. See attached image from a Honda service news article excerpt.