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2016 LML Denali 3500
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Discussion Starter #1
I wanted to consult the oracles on here after extensive research I’m stumped. Is a MAF reading of 60.5 at idle normal ? I have read a lot of conflicting things and I’m trying to figure it out.
 

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2016 LML Denali 3500
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Discussion Starter #2
I figured someone would jump all over this.
 

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I replied to your other post on another site. If your reading is in grams per second, the reading is too high. You should be in the low 40's. Either the MAF sensor itself is faiing, or the circuit for MAF has problems. Check for 5V reference and ground.
 

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2016 LML Denali 3500
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Discussion Starter #5
Ron I really never have looked at till recently. I just thought it was odd and thought it may just be the tuning? It runs fine no smoke now I have always said for a 200 HP tune it don’t come on down low hard at all but I have read to some it’s just a number. It has a [email protected] intake also so I wasn’t sure. I have no codes are anything either.
 

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I'm assuming that your idle is about 700. If so, there is something going on with the MAF. Check the 5V reference and ground, and if OK, then clean the MAF sensor, much cheaper than replacing it. Also, check to see if it is a GM OEM MAF sensor. Needs GMOEM, not aftermarket.
 

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I'm assuming that your idle is about 700. If so, there is something going on with the MAF. MAF measures air mass going into the engine, so the faster the engine runs, the higher the MAF reading will be. Check the 5V reference and ground, and if OK, then clean the MAF sensor, much cheaper than replacing it. Also, check to see if it is a GM OEM MAF sensor. Needs GM OEM, not aftermarket.
 

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2016 LML Denali 3500
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Discussion Starter #8
It’s original I have had the truck since new. I just seemed stumped why I have no code I will check the 5v reference but wouldn’t dirty read low? I’m just puzzled why it’s high when others say it should be 40. I also researched and have seen where a tuner said it’s just a number idk I’m just wondering if I have found my problem that has been around a long time. Is there any other signs i can look for since I have no codes. I have always said for a 200hp tune and even when it was emissions tuned you could stomp it and not light the tires. I just was looking the other day since I got back home and was like hummm that seems kind of high. I learn something new everyday with a dmax lol.
 

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2016 LML Denali 3500
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Discussion Starter #9
I will clean it in the AM and see what that does. Should I go through and check all the [email protected] piping? It’s always been loose around where the pipe goes in the box to the filter but the filter is tight to tube.
 

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I will clean it in the AM and see what that does. Should I go through and check all the [email protected] piping? It’s always been loose around where the pipe goes in the box to the filter but the filter is tight to tube.
Good idea on checking your S & B for loose connections, 60 is a tad to high 40 - maybe 45 MAF g/s is about where it should be.
Also check the condition of your airfilter if it has any holes or open areas

While your at it check and maybe clean your MAP sensor and compare it to BARO psi. Engine idling in park.
If the numbers are within 1 maybe 2 max, you should be good.
On your BARO psi compare that to your altitude, if it’s pretty close then that should be good.
Example below:
 

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2016 LML Denali 3500
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Discussion Starter #11
Ok so if there close and that’s good then what? What would be the symptoms of it being 60 ? That’s the part I don’t get ...could the tuning have it set that way like what is the symptoms because I have no cell and no smoking I’ll affects and the mileage is ok I guess. Could this be my down low power issue ? I would have thought low would cause less power. Idk this has me stumped ...Got to learn somewhere all this stuff online I read is conflicting.
 

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The BARO and MAP, KOEO, will be very close to each other. BARO is the atmospheric pressure, and MAP is the pressure inside the intake.
 

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2016 LML Denali 3500
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Discussion Starter #14
Well it all looks close well I’m fixing to clean it and change my oil and transfer case fluid. It may be fine idk just seems odd , I contacted my tuner about it and I am waiting to hear back it could be scaled wrong? Like I said what’s the repercussions of it beating at 60 no one has really answered that one. I though I would have a light ?
 

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Discussion Starter #15
Cleaned MAF checked all [email protected] connections everything is good so I guess a MAF rescale possibly ? Are a bad MAF ? Everything matched D to the R to the C
 

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I finally remembered to get a pic of my monitor.
 

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Cleaned MAF checked all [email protected] connections everything is good so I guess a MAF rescale possibly ? Are a bad MAF ? Everything matched D to the R to the C
Some tuners will go extreme on rescaling the MAF, all rescaling does is allow more airflow thru without setting off the P0101 code, it's not going to send more air thru.

I think Robs was around 50 max, with the HP your adding your tuner probably went extreme.
Factory is about 40 before you get a check engine light, mine has been about 45 with a clean airfilter.
But 60 is pretty darn high idling at normal Dmax rpms.

The plus with monitoring MAF g/s starting with a clean airfilter for a base line when the reading drops about 5-7 g/s idling its getting time to replace/clean your airfilter.

I'm not sure with the LML's (gmc502 I was thinking you had a LML)and the smaller flat airfilters what a stock MAF g/s idling is but 18.6 is pretty low, I think I'd be checking out that airfilter.
Another member recently with a LML his was around 32-34 idling with stock intake and stock paper airfilter.
The 2002 has pretty much the same airbox as my 07 Yukon (gasser no where near the MAF g/s as turbo diesels) and the LML's.
Good airflow is important for any engine with paper or aftermarket filters.
 

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2016 LML Denali 3500
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Discussion Starter #18
Well Tony contacted me and all he would divulge was that it runs good and no codes so don’t worry about it. So I guess that may be some of his Sauce Secret ....Well anyhow I cleaned tightened everything and I even put the block off back in the bottom of the [email protected] and it still stayed 60 but it seem to have better throttle response after I cleaned the MAF and put the boot in the bottom. Probably just all in my mind lol but Thanks to all with your help at least it made me check everything I did have some semi loose clamps but nothing changed the readings.
 

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2016 LML Denali 3500
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Discussion Starter #19
Also I’m on the dark side with no restrictions so who knows Tony says it’s good I trust him. Truck has been flawless for many miles and Tranny strong I have no complaints other than shitty steering.
 

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:thumb
If it’s running good with no codes then just continue to :grin2:
The MAF is pretty much the first one that might get dirty, with a aftermarket airfilter that’s something that might need attention cleaning once in a while.
 
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