I am a diesel tech at a Chevy dealer in southern Oregon. I recently got my hands on a couple of new AFE Stage 2 systems. I installed one on our owners 2005 K3500 Dually with a Juice/Attitude and a 4" cat-back exhaust. After the install it began throwing codes (P0401, P0404 EGR and P0299 underboost) All EGR and turbo functions were ok, however the codes would still reset after the second drive. Switching the system back to stock cured the problem... twice. In my efforts trying to figure this out, I took some comparison MAF sensor readings with each intake installed. With the AFE installed, the MAF readings were always LOWER than stock at any given rpm. It appears that these skewed readings are causing the MIL since the PCM isn't seeing what it expects to see. I suspect that since the intake tube is bigger, there is less air velocity at the MAF, or less air going through it and more air going around it, causing lower MAF readings. I installed the system on an 04.5 LLY later that day. This truck also had J/A and a cat-back 4". I experienced the same lower MAF readings after the install. I let the owner take it for a drive so he could give me his thoughts on the power/noise increase. He brought it back to me and demanded that I return the intake back to stock. He said that even in level 5, his truck felt slower than stock. I took it for a spin real quick, and came to the same conclusion. It had the worst turbo-lag I have ever felt (even worse than an 03 6.0 Powerstroke). I suspect that the lower MAF readings are causing the PCM to deliver less fuel, resulting in decreased performance. I returned his truck back to stock and he called me back later to let me know it was running great. So my question is to any that may have experience with the AFE Stage 2 for the LLY. Has this happened to you? I want to know how the system might work out in a stock truck, but I haven't had the time to guinea-pig one just yet. I have contacted AFE twice, and been told that the Tech Dept. will contact me, which hasn't happened yet. I suspect they are back at the drawing board. Anyone with experience with this product, please feel free to chime in. I want to figure this out. Thanks, Ben. Edited by: Max Payne

MAX PAYNE, I WATCHED A PORN AND HE WAS THE STAR. COME ON BEN QUIT LIVING THE LIFE THINKING THAT YOU ARE A PORN STAR

So the piece of pipe where the MAF sensor plugs into is actually larger diameter?

If so, then I can believe you'd lose performance. If they're going to change the pipe diameter, then the stock sensor may not read properly - it's calibrated for a smaller pipe. To run properly, I'd think you would need a recalibrated sensor. Just as you described - with the bigger pipe, I would expect more air to pass by the sensor without being counted... so you'd get a leaner mixture.

I HAVE CALLED AFE ABOUT THE SAME PROBLEMS, THEY SEEM TO BE VERY GOOD AT DIVERTING PHONE CALLS AND NEVER GETTING YOU TO A PERSON THAT CAN ACTUALLY ANSWER ANY QUESTIONS

I installed one yesterday and did a dyno run before and after and the gain was 3 hp and 18 foot pounds of torque the motor sounds a little louder but not bad no codes yet I just went up the cajon pass

OmniGLH,


One of the reasons AFE exists is because of the MASS Air problems at another company that caused the owner of AFE to go out and build his own systems. Even the filter service oil is different at AFE to keep from causing sensor problems. I have spoken to those in the know at AFE and the LLY system (as well as the location of the sensor on the LB7) has been designed around the sensor parameters to operate correctly, as the prevoius post has described they got more HP and torque and of course they caould hear the extra voulme of air being ingested in the engine as well. As an example AFE does not build a new F150 intake system like other air system companies, currently there has not been a way to build one and keep the service engine light from flashing, because of that they will not build a system that will cause lights.


Hope this helps explain sort of how they operate etc.


Mark @ DPPI

True, as I have also spoken to those in the know at AFE recently, and they have had to redesign the LB7 intake once due to MAF problems. He told me that the way they got it to work the second time is by moving the MAF as close to the filter as possible and adding restriction to the velocity stack in the air filter itself. That is why the AFE filter has a 1/4 inch lip in the filter neck. He told me that the system worked best with a stock diameter intake tube but they went with the bigger tube for the illusion that the bigger tube would look like it has more flow. We all know that it really can only flow as much as the necked down reducer at the turbo inlet anyways. But he told me that they have not tested the LLY stage 2 on any modified trucks, only one stock truck. He said they are going to possibly get in touch with Edge to work out a solution. This is as far as I have gotten with AFE, but they do sound like they want to help.

It sounds to me like the real problem that is being described here would be caused by AFE not calibrating their own MAF sensors??? Are they simply taking the stock MAF sensors and trying to sit it in the "new sweet spot" in the bigger pipe? That would certainly not the best way to generate consistant results. This may be why we see posts with less than enthuiastic results and why we see so many people questioning the need for aftermarket intakes.


Aftermarket part suppliers have been recalibrating the MAFs for the LT-1, LS-1 and LS-6 engine intakes for years now. That is the only way to get them to read consistenly. That helps to avoid the low flow sensor errors that you were seeing during the testing of the product because the baseline is tuned to what the computer expects to see even though more air is coming in.


So if it's throwing codes, I'd send it back and tell them to keep shipping you a new pipe until you get one that doesn't throw a code.


For those that are questioning how this thing can help make power on the intake side here's a little summary.


The MAF sensor tricks generate the "additonal power" by effectively delivering more air than the PCM thinks it's getting for any PCM directed fuel flow. That means we are playing games to leanout the air/fuel mix and therefore more power. The Turbo will always pull the same amount of air no matter what. The only thing the larger pipe might do is help keep the intake air down abithttp://www.dieselplace.com/forum/smileys/Big Smile.gif


Rick

ANY ONE WITH PROBLEMS LIKE THIS? I WANT TO GET A LLY STAGE 2 KIT BUT WOULD LIKE TO KNOW IF THIS IS A REGULAR PROBLEM.

It seems NOBODY reads the "filter testing bible" anymore? Just check on this forum all this many pages written about airfilters - really worthwhile to read!
In there it was clearly tested that NO OTHER FILTER works better than the original paper element! Sure you will hear more noise and get a lot of more dirt into your trucks engines - but you will NOT make more power. An exception to this rule might be only the super high horsepower rigs...
I would therefore save my money to invest in other things like exhaust, power modules, wheels...the list goes on.

Just my 2C

who66,


We have sent out 60-70 of the Stage II for the LLY and folks are calling us back and getting lower EGT's better MPG and overall increased performance.


As far as dirt if you get the Pro Guard 7 (which is all we sell for obvious reasons) it spec'ed out in the test that was done on this site at 99.23% dirt stopping effective, the AC Delco paper filter did 99.72%, a difference of 0.5% overall. That in itself is shows how well the PG7 works while keeping dirt out of the engine.


Mark @ DPPI

http://www.dieselplace.com/forum/smileys/Confused.gif AAAGGGHHH! Malhalkita, why, why, why bring up the ole air filter debate? Do we really want to rehash the same ole hash? http://www.dieselplace.com/forum/smileys/HiHi.gif JJ

Max Payne,


Did you build an 04' Crew Cab D-MAX that was lifted with a leer lid on it and sidewinder steps attached?

http://www.dieselplace.com/forum/smileys/Confused.gif AAAGGGHHH! Malhalkita, why, why, why bring up the ole air filter debate? Do we really want to rehash the same ole hash? http://www.dieselplace.com/forum/smileys/HiHi.gif JJ


Yeah, but that one is only at 13 pages so far, so rehashing the same ole hash in a new way might be fun. Might get to see some people get spun up and on the governor. Go for it.http://www.dieselplace.com/forum/smileys/HiHi.gif


Dennis

Mahalkita, sorry I mis-spelled your handle. http://www.dieselplace.com/forum/smileys/Cry.gif JJ

Max Payne,


Did you build an 04' Crew Cab D-MAX that was lifted with a leer lid on it and sidewinder steps attached? No, I didn't build your truck, Chevy did. But yes, I am the skinny one at the dealership that you are thinking of.

It seems NOBODY reads the "filter testing bible" anymore? Just check on this forum all this many pages written about airfilters - really worthwhile to read!
In there it was clearly tested that NO OTHER FILTER works better than the original paper element! Sure you will hear more noise and get a lot of more dirt into your trucks engines - but you will NOT make more power. An exception to this rule might be only the super high horsepower rigs...
I would therefore save my money to invest in other things like exhaust, power modules, wheels...the list goes on.

Just my 2C


I agree with this when using the stock air intake. However when I install a complete kit I get more power and better fuel mileage. I believe part of the HP increase of the kit is the air intake tube itself. I wonder if someone will make a kit using the new Fram Airhog?


I have also had a 01 torn down after 170,000 miles using a K & N and the dealer said the motor was perfect except for the blown head gasket. We replaced the gasket and put it back on the road.

Thats exactly what it is - a strong believe - grown from good marketing advertising over the years.. I have used the world famous K & N also in various vehicles and since it was more noisy and much more expensive it had to be better of course and it had to gave me more power and more fuel economy - but all I did was lying to myself. Because in reality it did not make any more power and also I did not save any gas (diesel) at all. I laughed at the diesel mechanic who told me many years ago that the original paper element is good enough and will give me the same power...now I understand how crazy I was all those years. Putting a bigger tube wont make a difference either, the engine will only inhale what it can use (or the turbo can use) even if the pipe is 10 times bigger. The original pipe is big enough, otherwise GM would have installed a bigger one.
I have gone through exactly the same thing on another forum for the Chevy Avalanche - GM did a good job in designing the intakes for those trucks. It needs just some people to believe that this is really true, I am one of them...now.

Rick Lance: I read some of your other posts saying you were disappointed in the fuel mileage (and other things) from the two 2004.5 LLY trucks. I was wondering if you have installed air intakes in either of these two trucks, and if so, any changes (milage, power, egt, engine temp, and engine codes)?

AFE Has finally sent me 2 replacement "prototype" filters to try. I checked MAF sensor readings on the same 05 that was throwing codes before. Stock intake reads 94 g/s @ 1500 rpm, AFE Stage 2 with original AFE air filter reads 77g/s @1500 rpm, and AFE Stage 2 with prototype filter reads 90 g/s @ 1500 rpm. The new filter does not throw codes. The old filter has a necked-down area in the neck of the filter that measures 3 1/2". The new filter is missing this necked-down area and measures 4". I believe that this necked-down area was causing turbulence at the MAF sensor which was causing the skewed readings. I also performed the same test on my own truck (LB7), and the MAF readings went from 77 g/s to 88 g/s, and my seat of the pants dyno says that the engine is now more responsive. All of these tests were performed under the exact same conditions, with brand-new filters. I do not have a part # for the new filter, as it still has the old # cast into it.

you sure you installed the maf faceing the correct way?

Read my signature, if I had a habit of installing critical components backwards I would have to look for another professionhttp://www.dieselplace.com/forum/smileys/Geek.gif

I haven't heard of any problems myself either. The tube where AFE mounts the MAF sensor is so closely similar to the OEM box it's about identical. If anything, it could be enlarged somewhat as mine sucks in the filter minder 3 clicks.





I'll call AFE today and get the real scoop...

JK, I have been dealing with AFE personally, my contact there is Saul. He has told me that they will probably fit all Duramax kits with the new filter that they sent me (with a 4" diameter hole, not necked-down to 3 1/2") I am proof that there ARE problems and AFE is trying to correct them.

Read my signature, if I had a habit of installing critical components backwards I would have to look for another professionhttp://www.dieselplace.com/forum/smileys/Geek.gif

Hey just because its your profession doesnt mean you cant make a mistake. things happen it was just a suggestion. i havent had a problem with the stage 2, mine works fine.

Have sold many afe's stage II to date, have one on my truck, have never heard any problems. swapped to afe on diesels after an k&n on a lb7 lost a maf when the brass inserts gave loose. Just a personal experiance that i have had nothing but good luck with AFE

Thats exactly what it is - a strong believe - grown from good marketing advertising over the years.. I have used the world famous K & N also in various vehicles and since it was more noisy and much more expensive it had to be better of course and it had to gave me more power and more fuel economy - but all I did was lying to myself. Because in reality it did not make any more power and also I did not save any gas (diesel) at all. I laughed at the diesel mechanic who told me many years ago that the original paper element is good enough and will give me the same power...now I understand how crazy I was all those years. Putting a bigger tube wont make a difference either, the engine will only inhale what it can use (or the turbo can use) even if the pipe is 10 times bigger. The original pipe is big enough, otherwise GM would have installed a bigger one.
I have gone through exactly the same thing on another forum for the Chevy Avalanche - GM did a good job in designing the intakes for those trucks. It needs just some people to believe that this is really true, I am one of them...now.



I disagree! GM and all the others do a balancing act! Cost versus Customer satisfaction. The factory air tube has a special more restrictive design to deaden noise and be cheap to make. Pure and simple this robs horsepower.


Headers make more power and very few cars have come from the factory with them. Most of the trucks perform better with 4" exhaust and no muffler, but none of the big 3 do that because of "cost versus customer satifaction".


We drive aproximately 2500 miles a week per truck. I can prove a fuel mileage increase because we have tracked every tank of fuel since new. As for performance and your thoughts, I would be more than happy to find a chassis dyno to test these air cleaner kits and invite you to be there.


GM even had a replacement box for the 01's because they did not flow enough and set off the filter change gauge!!!!


As for trying 1 on my 04.5's, I was waiting for K & N to come out with theirs and I am still not sure I am going to keep the LLY's.

Any more info on this subject

Seems that some people have had problems and some haven't. And it also seems that the majority of the people who don't have problems are the ones lining their pockets with AFE money.http://www.dieselplace.com/forum/smileys/smiley3.gif

I get nothing from afe I paid for my kit and have shared my experience with it 3+hp and 18foot pounds on the dyno not much power per dollar but the egt gauge tells the story

AFE is sending me a new filter out for the problem I am having.

I get nothing from afe I paid for my kit and have shared my experience with it 3+hp and 18foot pounds on the dyno not much power per dollar but the egt gauge tells the story


If your MAF sensor reading is lower than with the stock intake at any given RPM, you will be getting less fuel, hence lower EGT.

Looking at past dyno sheets, the one LLY that I tested with an AFE intake had a smoother and stronger curve than the others that I tested...

I get nothing from afe I paid for my kit and have shared my experience with it 3+hp and 18foot pounds on the dyno not much power per dollar but the egt gauge tells the story


Socal,


I would assume that you have a california truck, but we all know what happens when we ass-u-me. So, do you have a california emissions truck? I have there were problems with the intake, setting of the engine light, have you had those problems? With the cost diesel Ill take what I can get, even if it is 3hp and 18ft/lbs torque.

I have a california truck and not one problem ever with the intake t.I have never had my check engine light come on at all

I get nothing from afe I paid for my kit and have shared my experience with it 3+hp and 18foot pounds on the dyno not much power per dollar but the egt gauge tells the story


If your MAF sensor reading is lower than with the stock intake at any given RPM, you will be getting less fuel, hence lower EGT. I would think less fuel =less power my dyno run showed not much but some power increase

I get nothing from afe I paid for my kit and have shared my experience with it 3+hp and 18foot pounds on the dyno not much power per dollar but the egt gauge tells the story


If your MAF sensor reading is lower than with the stock intake at any given RPM, you will be getting less fuel, hence lower EGT.


I would think less fuel =less power my dyno run showed not much but some power increase


Not neccesarilly, there could be less fuel because there is more power. More bang for the buck, per say.


Thanks Socal, I think Ill get one of those...

Max Payne,


I have been talking to AFE. Today they said they are sending me a new filter? Is it just the filter or the filter housing as well? You describe in the past a 4" versus the 3 1/2". Can you shed some lite on this for me? Thanks

When you look inside The opening of the air filter itself, you will see that the one you have is necked down to a 3 1/2 inch opening that has a rounded edge on the inside. The prototype filter is missing this necked down area,measuring 4", and testing with a tech 2 shows that there are higher MAF readings at any given RPM with this new filter. I believe that the necked down area is causing turbulence near the MAF sensor, which explains the low readings. So even though you have a four inch intake tube on the stage2, you only have a 3 1/2" filter inlet and the turbo inlet is even smaller than that.


socal LLy...


I have a Stage 2 AFE on my LB7 and I love it. I am not trying to start a pissing match here. If you think that your truck is better with it, great. I think that the stage 2 LLY kit is garbage. It has cost me way to much valuable time trying to do AFE's job figuring out these problems. I am also not the only one to have this problem. It doesn't make the turbo any louder, and it doesnt lower the intake air temp either. So what good is it? Even with the new filter, it only runs as good as stock. I have done way to much testing on these. By the way, a 3 horsepwer increase on a dyno isn't even measureable, you could make twenty identical runs and each reading could be plus or minus 5 hp of each other. If you think that 3 hp is worth the $500 dollars these things things retail for, great. I would rather jack-off with a handfull of glass.....Edited by: Max Payne

i agree with you max payne. If I knew when I bought it what I know now. How course I wouldn't of purchased one. This is my first AFE. I have a neighbor that is very happy with his. I thought I give them a chance. Especially they were the first I found with one for the LLY. I am waiting for Airforce one performance to get the kinks out of there system. I have had a couple of K&N's and a few airaids no complaints from using their product. I can say that I got what I was looking for in their products. Thanks for your info.

When you look inside The opening of the air filter itself, you will see that the one you have is necked down to a 3 1/2 inch opening that has a rounded edge on the inside. The prototype filter is missing this necked down area,measuring 4", and testing with a tech 2 shows that there are higher MAF readings at any given RPM with this new filter. I believe that the necked down area is causing turbulence near the MAF sensor, which explains the low readings. So even though you have a four inch intake tube on the stage2, you only have a 3 1/2" filter inlet and the turbo inlet is even smaller than that.


socal LLy...


I have a Stage 2 AFE on my LB7 and I love it. I am not trying to start a pissing match here. If you think that your truck is better with it, great. I think that the stage 2 LLY kit is garbage. It has cost me way to much valuable time trying to do AFE's job figuring out these problems. I am also not the only one to have this problem. It doesn't make the turbo any louder, and it doesnt lower the intake air temp either. So what good is it? Even with the new filter, it only runs as good as stock. I have done way to much testing on these. By the way, a 3 horsepwer increase on a dyno isn't even measureable, you could make twenty identical runs and each reading could be plus or minus 5 hp of each other. If you think that 3 hp is worth the $500 dollars these things things retail for, great. I would rather jack-off with a handfull of glass..... We both spent the money $300 in my case but the benefits are small.What makes you love your intake.Are the gains much better on the lb7 .my gain came in form of lower egt

Mine came in the form of a louder turbo... Whooo Whoooo!


Its all good, as long as we're happyhttp://www.dieselplace.com/forum/smileys/smiley31.gif

I dont own a diesel.. but here are my thoughts:
ok so the MAF sensor is throwing everything off..
Why increase the side of the induction pipe when its NOT a bottleneck?

To my knowledge, when you have a turbo, the induction mods dont make as big a difference. "If a straw is not that restrictive, a bigger straw may not help"..

Ok so you wanna go with the bigger pipe, is recalibraring the MAF such a big deal?

And why didnt they catch this during testing..its such a base flaw!!!
Heck I could have told you that the MAF readings would cause problems if you changed the pipe diameter.. and I barely have the skills to do my own brakes.
Just wondering how they missed something so big!

Ram

I do not know how they missed it either, but Saul did tell me that they only tested the system on one truck before they began shipping them. "We tested the system on a local service manager's LLY and it worked ok?" I do not think it is because of pipe diameter, but due to the turbulance caused by the velocity stack of the filter only 1" from the MAF sensor, because removing the velocity stack helped it.

Just an observation, EVEN if it does have problems, I dont think that
AFE will just 'leave it alone', so I am pretty sure that they would
eventually fix the issue and then roll those fixes out to all current
owners of a 'defective' or 'flawed' product..

Yes you are right, that is why, if you read this thread, you will see that AFE built a prototype filter for me and are now sending them to all who have contacted them about problems.

Max Payne,


I also get the codes on my truck w/ AFE stage II. Would like to know the new filter # when you get it in hopes that it stops the codes.

Call AFE and have your reciept and they will send you a new filter for free.