They wouldn't lie, that is against the law. They would, however, adjust the truth to better suit their needs. Just like Eaton with their supercharger article, but thats off topic.

I didn't follow your link, but I understand what your saying. I just don't get how they do get some increased gas mileage if the stock paper filter is enough for the 4.0. I've done a bit of research toward CAIs, and have found them all to be useless as the stock air system isn't outflowed by the 4.0....or at least thats what I thought. But if there is any increase in mileage, then the K&N does indeed do somthing, and the stock air cleaner system isn't as "good" as others have made it out to be.

You "clean" them, its not just washing. You rinse them out, then "recharge" them with oil you can buy from K&N. They sell "recharge kits" at any place that sells the filters.

 

just disconnect your battery and reconnect it, its pre obdII so it will do a computer relarn with the new sized exhaust maybe if your lucky it will fix things. ive had open exhaust from the headers with no problems you are speaking of. there is definitly another issue in his case

 

Thank u.....we're back on topic (sorta).

 

That is my point...you clean them, then re-charge with their $18 kit, then they promptly let in more dirt than a paper filter and provide zero benefit in mileage or power in trade. I can't think of a worse deal than that. $70 for the filter, $18 each for the recharge kits...and an engine worn-out before it's time.

No air filter from any maker works better than the paper element that was shipped with the car. It is a "zero sum" game - you let more air in, you let more dirt in. The paper filter is already at the correct size to allow all the air in that the engine can use at the END of the filter's life, not the beginning. Any company that tells you otherwise is lying to you...no matter what the law says.

 

This is interesting information. I'm glad you are posting it.

I still have to laugh, though. At the top of my browser window there is a very large advertisement for an "AIRAID" oil free aftermarket air filter.

 

so i just went wheelin this weekend and after ward im still have that idle issue i cleaned the iac sensor . any suggestions

 

You'll notice they don't soak air filter masks with oil...or the sub-micron air filters in any common woodworking shop. And we're talking about our LUNGS here, not some lump of metal.

Tractors and trucks have oil-bath filters because it is the cheapest way to get good filtration. But those filters don't work by soaking an element with oil, they work by forcing the heavier particles through a kind of air plenum where they drop into a pool of oil and they use a secondary paper element filter for the small stuff. I have one of these on my 1964 Case 830D (diesel) tractor. The tractor would run perfectly without the oil-bath filter - all it needs is the paper element - but the paper element would require changing more often. Not much more, but farmers are notoriously frugal. I use the oil-bath because I'm cheap and don't want to buy more paper filters or spend 45 minutes disassembling body metal parts just to get at the filter.

But the old style oil-bath filter gave rise to the CONSUMER idea that soaking some kind of filter with oil was somehow better than paper...but this is because people misunderstood how they worked. Tractor filters are "oil-bath", not oil-soaked.

Tractors, being designed to operate in the DIRT for their entire lives, need the best filtration you can get. This is the system they all use - oil bath for big stuff, paper element for fine particulate.

K&N's, on the other hand, aren't even a fine-mesh paper element. They are supposed to be some kind of re-useable element material that you soak with oil to fill in the holes enough to actually grab some dirt as it is going by. Pour some oil on some household window screen and look it over. This is how K&N works. This is why they work better when dirty...the holes get smaller. I am truly sorry if this offends anyone using K&Ns. I had one, too...until I got seriously looking at the thing. Then it hit me that the whole idea is ridiculous. Worse, my F350 V10 burns more oil than it should with 110k on it because th DPO used a K&N all it's life. I'm paying for their junk right now with a puff of blue smoke every time I start the engine.

I think K&N is a deliberate fraud. Not just a bad product, but a bad product the company KNOWS is a bad product. I believe they are scam artists and would say so to their face. I wish I had one laying around - I'd cut it up and take pictures and post them on this forum.

Now I'm done with my rank. I beg forgiveness if I have irritated anyone - especially anyone that runs a K&N. I threw mine in the trash...I hated to do it and ALMOST ordered a "recharge kit" because I was so sucked into their hype...but then just threw it away. It felt almost like quiting smoking.

 

if anyone is puting a exhaust on their jeep to make it more powerful just stop now and leave it stock.
The only reason I put exhaust on any vehicle is to make noise.
unless you are speaking of a turbo or supercharged vehicle a larger exhaust will only hurt performance.