I see a lot of positives so I am getting my pcm tuned. Are their any negatives that come from it?

 

None.

 

POOR MILEAGE
because you have your foot in it for the first tank or 2 playing with your new found power!

 

🤣🤣🤣🤣🤣 glad to hear it.

another question I have is why didn’t GM tune the PCM in the first place?

 

good question, did mine many years ago, never had issues and i'm happy with the result.

 

What, Really?
It's every automotive manufacturer not just GM. There are many reasons to "de-tune" the performance of a particular engine & transmission combination.
-EPA ratings, Emissions, Reliability, Insurance, Mileage, etc...
To produce a balance between performance, durability, and marketing needs...
To fit into a particular regulatory class (in the US, for example regulations change with the load capacity of a vehicle)...
To meet insurance requirements (horsepower limits for example)...

 

The beauty of "the tune"

If unhappy you can go back.

 

yeah but I don’t think I will from reading all the comments in the forums. People say this is the first thing you should do when you get a H3. So I am just waiting for it to come back in the mail 😁

 

None....... you will be wondering why you waited so long.

I went with the hand held Banks Tuner for my 09 Alpha, can change it any time, as many times, as I want.

 

Doc, you got me interested so I went on Banks website and can't find any listing for Hummer under their tuners or programmers.
https://www.bankspower.com/c-50-prod...e-tuners.html#