04black150

My 04 f150 with a superchip and flowmasters and it has 70k on it. Last january i put on a k&n CAI and ever since the installation ive had a major loss in gas mileage. Also when i accelerate just a tad bit faster than usual from speeds from 0-40 the the rpm's fluctuate (jump down a little, then back to normal) a little when i initially step on the gas. It doesn't fluctuate a lot, just enough to where i want to know what the problem is because i know that its not supposed to happen. I figured it might be because the fuel sensor on the intake might be dirty from when i changed it out of the stock air tube to the k&n filter tube. But I'm not a mechanic so any opinion would be appreciated.

10SEC93GT

Dont hold me to this, Im a lil new to the F150's as well but alot of experience with mechanic work. I have read that when u put a CAI on a 04-06 F150 it will lean it out unless u have a custom tune, whether it be a programmer that was sent off and had the custom tune loaded in or a dyno tune. Did you disconnect the negative battery cable for at least 10 seconds to reset cpu after install??

jwsboard1

Im not an expert by any means but iv read that the oil from the kn fillters can make the maf nasty might be worth cleaning it. Easy todo.

Mod (Ret.)

Totally false, and a large internet myth!

Contact K&N (google for the web URL), and talk with a tech. They are aware of any issues of possible lean mixtures, and can set you straight.

By all means, ignore any rumors of K&N and MAF issues! Once on their site, read their FAQ section. You'll see their statement on this.

I wish folks would stop referencing these myths. I've used K&N filters for years, both on my vehicles and my Harleys. My current harley has over 135K ON THE SAME K&N filter, as well as 83K on the F150 truck K&N CAI and I've never had any issues with using them.

The only way this could happen is if folks over oil them. Follow dirrections when cleaning and oiling, and you'll never have a problem.

jwsboard1

Good to know....i was wanting to put in a kn drop in to go with the gotts mod butt after reading all of the "troubles with oil" everyone talks about i didnt want to have troubles. Thanks for the info. Its one heck of a rumor its posted all over the forum.

jerrybizzle

Could still be a lean issue though, without custom tunes or a canned cai tune. Superchips doesn't have a cai tune. Some have canned cai tunes such as diablosport, or u have to have a custom tune written.

10SEC93GT

My 08 Limited 5.4 has airaid cai and exhaust. I never reset the cpu and it seems to run just fine. Picked up power and runs just as smooth as stock, no programmer

ronmon

I am planning on adding a CAI to my 04 5.4, and have heard stories about the oil from the filters causing problems with MAFS. Also, do they make a CAI that is oil free? Are custom tunes required for a CAI? I have also looked into a TBS and if this would give me the gains I want, HP and MPG, and if I installed one of these or both will the computer reset itself? Any Answers?

speeddemon86

Stay away from the spacer they are useless. I have a k&n cai on my truck now for over 3 years and 100,000 k or more with zero issues or problems. Never had a problem with the oil on the maf. Just don't go over board with the oil. It only takes a little bit

WorknProgress

I just installed a k&n CAI on my 05 5.4 3 days ago. I don't have the gas mileage issue but I do have the RPM thing. It just seems like it takes longer to shift into second but that could be due to the fact I'm running the "tow" tune on my Gryphon. Because of your modifications you may require a custom tune so that everything works in harmony. I've ordered mine from Power Hungry Performance, until then I won't run my truck too hard.

Just my .02