I noticed while reprogramming my 2009 Chevy Avalanche LTZ 5.3L.
I am only getting 84% of my throttle at wide open throttle?
I have drive ability issues no codes.

What sort of drive-ability issues are you having?

Is this 84% reading at the accelerator pedal, or actual throttle position?

Does the throttle percentage sweep smoothly, linearly, and predictably with actual accelerator position, and it just ranges 0-85% at the very end? Does it hit 84% about 15% from the end, and just not push any higher?

At wide open throttle peddle to the floor only 84% total throttle usage. Truck has 148,500 miles on it, it runs great just not understanding why the it is only getting 84% and not 100% not sure if the throttle body has carbon build up maybe and needs to be cleaned or is it a drive by wire issues?

We're trying to figure out if you are reading the actual throttle pedal position or if you are reading the drive-by-wire throttle position. Unplug the throttle body, turn on the ignition (without starting), and measure the same thing again. Does it give you a reading or does it give you nothing or an error?

Hold on, what exactly were you reprogramming? Using what programmer?

Just don't come in here throwing problems at us without explaining what, who, why, where and when. Prime example: programming can cause issues.

Good point, I hadn't thought of it this way.

I wonder if this is one of those cars that restrict engine output in certain conditions, for example: valve timing, ignition timing, throttle tip-in, RPM limit, and maximum engine output is limited in the big Lambdas in reverse and neutral. I can't say I've scanned one with the engine off to see what happens.

What were the conditions during your 84% findings, engine on/off, gear selection, etc. . . . ?

My bad let me explain the Programmer is for adjusting for larger then factory tires. And I can tune for towing and for better gas mileage.

What kind of tuner is this?

It uses Bluetooth from the OBD2 port to any device like a tablet or old cell phone.