Huge hesitation, mechanically inclined. Please help

[Brian Wilson]

I have a 2007 yukon denali 6.2
6 speed w/o AFM or DoD.

I have noticed a hesitation when taking off or at low speeds. It is always there and has progressively gotten worse. It's to the point I am afraid to pull out on the road with less than 1/4 mile of room. It has a great idle. It has never died on me (but I'm afraid that will happen next).

So far I have done these things
Fuel pressure check. 60 psi and 45-50psi running.
Cleaned throttle body.
Cleaned mass air sensor (is there a way to test this sensor with a multimeter) one resistor looked different than the other one.
Tested injectors. All good and clean, not sticking shut or open
Ac Delco plugs and wires changed
With factory replacements.
Compression test. All cylinders at 155-165psi
Tested ignition coils individually. All good.
Checked cats with pressure gauge. Very clear. Not a problem
Pulled valve covers to check for broken vave springs, bent valve or rod, or clasped lifter. All good
Tried taking off in trailor/tow mode, same issue but slightly better due to the higher shift rpm. Also tried to run in manual shift, same issue.

I tried running with my brother hooked to a snap on mods scan tool. No codes, no misses, fuel trim looks good, or signals are good and everything else looks great. Even when the truck is bogging down taking off.

It feels like I'm trying to take off in 4th gear honestly. The engine will not build rpm very fast at all but it doesnt drop rpm either. It doesnt try to stall or die. But I'm in 1st gear. I can feel the shifts and count them.

Does anyone have any ideas? I have tried to be as informative as I can. And I have tried everything I know.

 

[Brian Wilson]

I also changed the air filter. This is a bone stock yukon except a flowmaster 50 series that has been on it for years. This problem just started a month ago.

 

[M3kanic]

I would suggest a tune or a 6.2. That sounds exactly why I hated my wife's Tahoe. I have a 02 suburban that is tuned. When we got my wife a 10 Tahoe I was complaining about the same thing you are. I actually traded it in for a 10 Denali XL. The 6.2 is light years better and because I'm not stomping on the gas to get off the line I am getting better mpg.

 

[Brian Wilson]

I have the 6.2
It use to be a real powerhouse but something is wrong. I just can't figure out what it is. I thought engine at first. Then I thought transmission but the tray fluid looks great.

 

[#1taho]

Use the scanner to check you mass air flow tables. By your description the dark spot on the sensor it's no good. I would replace it.
But look at what the numbers on the scanner are telling you first.

 

[osiris94ej]

Cleaned your throttle body yet? Carbon buildup can cause some driveability issues. Other than that I'm not sure I know of anything else without doing some playing around with it.

Sent from my SM-N920V using Tapatalk

 

[Brian Wilson]

Going to try swapping the mass air sensor today
It just looks like 1 resistor is shiny and dark and the other is white and cloudy colored

 

[Brian Wilson]

Since they are resistors I should be able to ohm them out correct?

 

[Rocket Man]

I'd try a new MAF. My 02 Denali 6.0 had a random stalling issue that had me stumped for months and the MAF was the problem. It was so random that I doubt I could have tested it with a meter. Sounds like you don't have much to lose, they're only $70 or so. I also had no codes.

 

[Brian Wilson]

Thanks for the advice. Going to the junkyard today to get one. I hope it's the same as the 2009 escalade