I have an AFE CAI and when its at an idle it makes a tatatatatatatata choppy sound really fast and constantly sends the idle up and down. It has gotten to where the idle is now staying at 1500 rpm. The noise also sounds like it's coming from the air filter itself. When I come to a stop sign it does it and I have to mash on the brakes to get the damn thing to stop. My truck doesn't do this with the stock air intake already put it back on and checked it out. Didn't bother me at first but now it's doing all the time. The CAI has about 2000 miles on it so I don't think breaking it in is the problem. It's done this since the second I put it on btw. Anyone know what the problem is?

 

It almost sounds like a baffle.

 

Sounds like an air leak near or on the filter or just a bad filter all together. Have you started the car n popped the hood to see if you can find the leak if it is one?

 

You didnt happen to jostle around the MAF when replacing it did you? Im trying to think of other things besides a vacuum leak, as that will sometimes hiss if big enough.

1st things first, go over your install, make sure you didnt leave anything unplugged like vacuum hoses, the air filter is sealed correctly and the screen is on the MAF. I dont know if 02's have air intake temp sensors(I havnt replaced anything on my truck so I havnt even looked lol)...if you left that out you could be having issues there also.

Other than a vacuum leak, i dont see anything else making an audible noise other than mechanical failures.If you have a voltage meeter, get a reading of the MAF and see if its reading correctly. It should be around .75 V at idle if I remember right. Thats an easy way to check if your maf is the issue. If thats not the issue and there no Vacuum leak, go back to the PCV/IAC valves and check those.

 

It's def not the MAF. I unplugged it to see and my truck wouldn't idle and was dumping black smoke. The PCV hose is identical to the stock one. It did have a temp sensor but it sucked the rubber stopper around the sensor of and is now lodged somewhere inside the throttle body. I've installed it several times. Even put the old intake back on and runs no problems. However, the hose that connects the throttle body to the main body of the intake tube seems to be the rising issue. It plainly states not intended for FI use. Didn't see this until last night. Why would that hose be making all the difference. There is no whistling. It sounds like your taking a wrapping paper tube and hitting it against the wall as fast as the RPM's of the motor. And it's freaking loud too. This is such a stupid problem to have

 

Several times. I'm starting to think it's the entire intake cause I took the air filter off and it still makes the noise. Look at the above reply for more details.

 

<_< double post...

 

I had the same problem with my K&N intake. There is a little black box thats an Idle Air control valve that runs off the intake tube to the throddle body. Its located under the plastic shroud.With the K&Ns it says to remove it as its not needed. My truck only did it in the winter and i read on this forum to put that black box back on, and the problem has never happened agian. This could possibly be the problem, but being diffrent intakes maybe its not. worth a try though good luck.

 

LOL!! The directions these companies give is mind numbing. That "little black box" is what meters the air to the IAC. The IAC is what keeps your car/truck idling normal. Iv seen the same thing with other companies claiming you need to remove the maf screen when putting a CAI on because "its a restriction".... the whole reason that screen is there is to provide laminar airflow to the MAF so it can get the best possible reading.


My advice to the OP:

Take the entire intake off up to the TB and drive it down the street and back. As long as your not having a dust storm it wount heart anything. See if you hear the rattle, if you dont then you have isolated the issue. I have a feeling that your CAI isnt the issue, given what you have checked already.

 

That's exactly what I was thinking. I had to dig around in the garage but I found it and I'm gonna put it back on tomorrow. AFE told me to do the same thing. The only difference in design between AFE and K&N is cost haha.