I just installed a K&N CAI on my 2004 Mach 1. I am having some low idle problems, and a few times the car stalled out idleing up to traffic lights. The idle will fluctuate between 500 and 800 RPM with the drop to 150 rpm randomly. I have even had the car stall out 2x. I seek your input on the situation. Anyone have had the same problem or know of a solution, I would love to hear what you have to offer.

 

It seems that removing the screen causes stalling with manual trans. Auto cars generally do not slip it into neutral and coast or push in the clutch and coast to a light. Those where the times I seen the problem which you can do 1 of 2 things. First change your driving habits or find a way to have the screen installed. I took my air horn to a cnc mill and removed the thickness and stepped the air horn so the rubber lip located the screen assembly in the id of the air horn.

 

I had the same issue with the K&N, even after I put the screen back on. I found that the problem is much worse when going above 40MPH, so I would downshift and try to keep it in gear until I was going below 40 and it would never stall, every now and then the RPMs would drop down below idle but it would come back. Eventually that got old and I just went with the C&L, couldn't be happier.

 

I've had my K&N intake on for about a day now and have driven about two hundred miles of city and freeway, without any problems. My car idles around 800rpm. The only mods I have though are the K&N intake, a PHP intake spacer, catted x-pipe, and SLP catback.

 

Auto?

 

i would be more than willing to say the air leaving the pcv valve isnt getting into your intake. I had this problem with one of my cars a year back when i installed a oil catch with a vented top. has to be a sealed system, check the connection

 

I had this same problem with my mach. I put the screen back in and it seemed to help a little, I got it dyno tuned and all was great!

 

Nope, 5 speed. That's why I put 200 miles on it in one day. Way too fun to drive

 

LOL. Well not everyone with this intake is having issues with it but the majority are, you could be one of the few.

 

I wonder what it is about the K&N design that could be causing the issue. I mean, it's just a friggin air tube. I only know of four intakes made to utilize the shaker (JLT, C&L, K&N, Steeda) and I was under the impression that none of them retain the screen.

Perhaps, by some weird anomaly, could the intake lean out the mixture too much under certain conditions?