K&N filter causing reduced power

[boothybunch]

Originally Posted by walkwavy

Been there - done that. 1st GM has a service bulletin not to use any filter other than their own and they name K & N as not to use. 2nd K & N has a notice not to use their filter unless you do the entire air intake system. K & N returned my money for the filter.
Oil from the filter getting on the sensor is one of many stories. The actually problem per GM and K & N is that too much air is coming into the engine. Both their stories - not mine. Buy a G M filter is the solution.

Do you actually know how STUPID that sounds ????

A diesel truck getting TOO much air

[heymccall]

It may sound stoopid, BUT, the ECM looks for a given value from the MAF under all conditions. The aftermarket filter allows too much air, sending the expected values for air volume out of range, resulting in a CEL.
Owning LLYs and LBZs, one of the easier mods is to swap in the power core filter from an '06 into the '05s, BUT, even that will illuminate the CEL. GM did release a revised calibration allowing such a simple mod, but, I returned them to stock.

It ain't stoopid, it's reality.

[boothybunch]

So the duramax must work ass backwards to diesel's over here.

[Hibbs max]

from what i was told the only reason the k&n filters flow more air is because they have bigger holes in them compaired to the stock filter hense letting in more dirt

[heymccall]

Originally Posted by boothybunch

So the duramax must work ass backwards to diesel's over here.

We have the same junk you do. The MAF sensor output goes out of range when using a different air filter. How many of your back asswards diesels over there utilize a MAF sensor to calculate air volume?

[walkwavy]

Originally Posted by boothybunch

Do you actually know how STUPID that sounds ????

A diesel truck getting TOO much air

Go champ!

[D_R_C]

What I found on my LMM and pretty much since the LMM came out was if there was over about 40 MAF g/s at idle it set off a check engine light P0101 code. In mid 2008 GM had a update recalibrating the MAF which now any readings over about 45 MAF g/s @ idle will give you a P0101 code.
The K&N is thin and flows to much air and in most cases you will have issues.
You can hold a K&N up to the sun light and the light will go right thru.
With the aFe proguard 7 you won't have this issue, at least I don't.
With the stock air filter the MAF g/s was around 26-28 @ idle.

[oldred95]

If you have EFI live turn off P0101 and run whatever filter you want or you can leave the sand sifter out all together. The K&N and even the stock filter for that matter seem to keep out the sticks and rocks and not much else. Even a trusty AC Delco is no match for the dirt and dust we have out here.

For what its worth the ones I've seen that were really picky about only wanting to run with an AC Delco filter were also starting to clog the EGR cooler and valve so the air flow through the engine wasn't exactly what it was supposed to be. With an AC Delco filter it would go ahead and run but anything else and it didn't work. You can get a P0101 without a P0401 and still have blockage in the EGR system.

[heymccall]

What does the EGR have to do with the filtration afforded by the air cleaner element? Bypass the PCV if premature EGR caking/ coking is occurring.
Poor air filtration will amount in excess ring and cylinder wall wear, lowering compression.

[oldred95]

Originally the EGR systems were setup to be on at warm idle. This worked fine as long as the truck didn't have excessive idle time which caused the cooler and valve to coke up. Then there was the reflash that changed the EGR system so it wouldn't run with extended idle to prevent coking but it still cycled on and off occasionally. The ECM is constantly monitoring the air flow into the engine with the mass air flow sensor to make sure there are no leaks within the charge air or EGR systems. What it doesn't do is have a way to measure the amount of restriction through the EGR and the parameters for the P0401 aren't quite sensitive enough to trigger a P0401 even when there is substantial coking in the EGR system. I pulled my hair out of a P0101 on a 09 LMM until I was enlightened on how the mass and EGR all work together. After replacing the cooler and cleaning the valve the truck had no more issues with the P0101 regardless of what air filter was used. Once it got out of warranty it got a DPF and EGR block off and P0101 got turned off for good measure.