Some may not like to hear it, but a FILTER that flow MORE air in the same space! Allows more contaminates.
Also Oil form filters can and does contaminate both MAF sensors and more importantly O2 sensors. Some MAF sensors can be cleaned but O2 sensor once the oil hits the sensor will yeild incorrect output!
Two points here an incorrect O2 sensor output can and does effected fueling.
Second point many fail to realize is MAF sensors are not ABSOLUTE! In that I mean just slapping a MAL on an application does not result in Mass Air Measurement! It will give an output, but all MAF sensor in production application has a "Characteristic curve." That CURVE is output in voltage vs. MASS AIR FLOW. Changes in Ducting, flow, and Air cleaner characteristics, will change the SENSOR output vs. MASS OF AIR! )
When the air cleaner is changed, it may not be a straight linear SHIFT in the characteristic curve for the MAF output! So it may be well within a given amount of change at some Speed and load points and well outside the amount needed for a "CEL MALF" at other points!
But without a doubt changing an Air cleaner that changes flow, effects MAF sensor OUTPUT!
One last thought for those that think they know how a MAF works, modern MAF systems in most application are also SPEED DENSITY under some conditions!!
During reversion a MAF sensor cannot always be trusted, so some speed density tables exists in software, for those points where MAF output appears to OUTSIDE of a window where Speed density "predicts" Mass of Airflow.
Changing an AIRCLEANER to a high flow can set a CEL.
your first hand experance have any data to back it up?
oh thats right. none.
just a sucker that fell for KN marketing.
Most of you are forgetting one important fact. The GOVERNMENT has a lot to do with OEM tunes or calibrations as some of you smart, old engineers dub them. The stock parameters on a GS are horrible to say the least. If you gave the key fob over to someone who has never driven a GS, they'd never know this car has 295 lb ft. It could be soooo much better. A better tune on this car would result in even less gas mileage and GM has to have a certain amount of cars that get decent mileage. As far as GM is concerned, someone who buys a GS isn't looking for CTS-V performance numbers, so the GS suffers.^^^ Well said.
Most of the things you mention probably sound so common sense to people like yourself it sounds absurd to even mention it. But I don't think the majority of people truly understand it to the level you just described.
I live in WI and I have access to 93 octane fuel. Just by having access to that fuel means that I could find ways to improve the performance of any factory calibration on any vehicle while maintaining the long term durability of the factory calibration.
BUT
That does not mean that someone who lives in the rural parts of Canada could say the same thing. The "premium" fuel choice might only be 89 octane. Eww... As a tuner myself, I would not even touch that person's car.
So I completely understand why manufacturers don't sell cars with calibrations optimized for Eric in WI or Joe in Alberta.
That is where tuners fill the gaps. Honestly, the main reason tuners knock factory calibrations is to promote their own services. It is the sad but honest truth.
Hang in there buddy!
Well we got our first k&n filter flame thread out of the way I think we are on the way to becoming a car forum.
Most of you are forgetting one important fact. The GOVERNMENT has a lot to do with OEM tunes or calibrations as some of you smart, old engineers dub them. The stock parameters on a GS are horrible to say the least. If you gave the key fob over to someone who has never driven a GS, they'd never know this car has 295 lb ft. It could be soooo much better.
A better tune on this car would result in even less gas mileage and GM has to have a certain amount of cars that get decent mileage.
After a good night’s sleep I decide to add a couple of comments. One thing that has always been a "sore point" when reading forums such as this are the "tuners" and modders, that make statement like “the factory tune" sucks. . And "my change" could not possibly effect THAT!
It is not a factory "tune" but a calibration.
What I always ask is why does a person that hasn't lived with an engine in development for several years think they know more than the guy that did the job.
Engineers that do calibration want the most performance and drivability they can get from a package. They not only know "how the software works" but they invented its function. And they then spend several years in development in All temperatures, altitude, and road trips all over the US and Canada doing testing and DURABLITY work on these packages.
When something is less than "optimal" there is normally a very good reason why! Durability is a prime reason to limit output. And compromises are "KNOWINGLY" made when calibrations are developed. Sometimes it's hardware limitation and sometimes limitations that effect overall performance are a result of a narrow band "side effect". (Something that only 1 in a hundred persons might put their vehicle through! But for production, 1 in a 100 failure is HUGE)
I know the guys that do this work, they are very smart folks that understand the WHOLE system and it's limitations. (they also must comply with "other" hardware limitations, such as transmission load requirements! Trans guys hate POWER~a small joke, but they would shift under no load every time if they could!)
Development and calibration is always a choice of what is most important. For engine development and "calibration", that is durability of the engine and vehicle FIRST.
Tuners do not have that limitation. Getting more power is the goal for aftermarket tuners. They may not even fully understand the compromise they make when adding fuel and spark in a dyno environment, and how their changes impact long range durability!
Lastly, engines are not constant. Testing and calibration take place with not only NEW engines but aged parts that must continue to function correctly with miles. A new combustion chamber has far different requirements for spark than one with "aged" deposits. O2 sensor output changes over the life of the engine and has direct impact on fuel control over that engine LIFE. Production release must encompass all of those "life cycle" variables when released. "Tuners" deal with a very small sample of an engines and therefore have limited experience with aging of components, yet they GUESS at how their changes will effect durability.(ECM time is measured in MSEC. and many functions in modern software have "look ahead" features that are calibrated, and predict a range of output expected. Tuner cannot know nor even begin to use the tables that predict "look ahead" function.)
That is why I have said, for folks that want to "mod" and tune, just do so knowing you might also be limiting durability of some component in the system.
When an OBD II code comes on and you don't "think" it had anything to do with your change, you might just not understand "everything" you know. Engine calibration is a very complex system and more interrelated across the vehicle. ECM, TCM, BCM, and Cluster control modules all share and make changes based on inputs from those other control moduals. If you don't know how it works it's impossible to say, that change would not "effect" that problem.
I hope my input here can help some make more informed choices when making "modifications" to a calibrated system.
That TSB has been around for a long time, at least 10 years. I think I even posted it earlier in the thread. You'll probably lose, it's a common problem of filter oil covering the elements in the MAF and giving incorrect readings.Just be warned. 2012 GS...The dealer didn't cover a repair of the MAF because of the K&N. It cost me almost $600. I'm going to sue them in small claims court because there is absolutely no proof of this. I've had a K&N in every car I've owned...never had a problem. Either way, it's a real pain in the ass. Take the filter out before you bring your car in for service.
That TSB has been around for a long time, at least 10 years. I think I even posted it earlier in the thread. You'll probably lose, it's a common problem of filter oil covering the elements in the MAF and giving incorrect readings.
Sometimes new K&N's come a little over soaked... you can sometimes see the oil on the rubber gasket around the filter. I make a habit of wiping a new filter with a paper towel before installing just to make sure there isn't any extra oil.
I've had the drop-in in the GS for year now with no problems. For that matter, I've had K&Ns in almost every car I've owned (over 30 cars/trucks at least) without any problems. Then again, I never keep the car long enough to need a re-oil 😛
Adam