Very high RPMS after dealer did the fuel injector flushing

[aztec]

Hello everyone I bought a 2012 gmc Yukon Denali and took it to the dealer to do the transmission fluid change and the transfer case flushing , once I was there the guy at the dealer recommended the FUEL INJECTOR FLUSHING at the beginning I was kind of hesitant about it but I agreed after all..

As soon as I drove out of the dealership I notice that my rpms were too high downshifting and also

My truck would go up to 25 mph without me even pressing the gas pedal

Once I got to the freeway same thing happened I was around 65 mph and let go of the gas pedal and stayed there like it was on cruise control..

So I took it back to the dealer and they drove it and agreed that the rpms were too high , but they can find the problem they said they checked all their work and everything was fine, but I am 100 % sure it was not like that when I took it in.

The only thing is that my check engine light was on with a code 0102( I believe ) which is the mass air flow sensor ( previous owner put an aftermarket filter ) and now they are trying to blame it on that, but my truck Never did that before they cleaned the injectors.

By the way they are trying to charge 125.00 to get it diagnose.

This is what the report said they did :

“ Installed fuel injector flushing tool and ran through cleaning cycle, installed 44k into fuel tank to

Balance of fuel system.”

Does anybody have any idea what is going on ? any suggestions? do you know if they have to remove then throtte body off maybe they didnt put back right?

By the way the truck still at the dealership, trying to find out what is going on.

Any opinions will be greatly appreciated.

 

[MichaelSE]

Sounds like a shit service department, or just tech, that is trying to cover up a mistake. I only have a few cheap suggestions that probably won't work but might be worth trying to you.

Get the CRC MAF & throttle body cleaner set, I think it's around $9 at Wal-mart, and clean them both. The MAF sensor is easy to get out, it's just 2 Torx screws. It's delicate though. The throttle body is also easy, in fact the hardest part is shaking the plastic loose. Take it all the way out and clean the plate and make sure the gasket looks good.


Judging by the code it might be an airflow problem. Maybe a vacuum leak?
But judging by your symptoms on the highway, it might also be a TPS issue.
Or maybe they just screwed the MAF and it needs replacing. IIRC they are around $70.

Best of luck resolving it.

 

[aztec]

thank you for you input MichaelSE , i will wait for the outcome on monday and take it from there.. i will try the cleaner you suggested.
i really appreciated.