Welcome to the GLA forum Arthur. You didn't mention where you are located nor which model GLA 250 you have (FWD or 4-matic AWD), that could help in responding to your question. Please consider adding those two data points to your member profile for future discussion, from the User CP link on the upper right on most browsers.

 

I live in Boston, MA and it's a 4matic AWD model.

 

What Turbolink was saying update you profile. Click on "User CP" near the top right and then click on "Edit Your Details". Near the bottom fill in your "Location" and "Car Year & Model". You may wish to fill in any other areas on the page. This helps when asking questions as the replier can better answers knowing your location and GLA.

 

In the upper right corner of the forum note a search box... put is 'throttle lag' or 'transmission problems' you will get search results on the several threads that have discussed issues and solutions. I would say that considering you have a 2015 model the tranny software update would take care of most of your issue.

 

My long time mechanic friend told me to install a ECU Tuner in it, as well as a blow off valve.

 

... as well as a blow off valve.

You may want to try this, I installed it and was surprisingly effective in eliminating the turbo lag and the "clunky" DCT up shifting between first and second.

It is a pneumatic diverter valve by GFB, what it does is to modulate the diverter valve when transitioning from dumping to spooling. The OEM device is nothing but an actuator, either ON (spooling) or OFF (dumping).

 

If it is just an issue of initial lag a Pedal Commander will help tremendously. Easy to remove when bringing in the car for warranty work! >

 

I also have a GFB DV+, People compliment me on the way the car just keeps pulling the same even through gears. Very recommended, just for the sake of protecting the OEM system from damage since I'm tuned. Also, I would not use Pedal Commander, how much do they cost anyway?

 

Nice, I get both tomorrow. Can not wait, since I put like 10-15k a yr on my cars. Anyone have good suggestions on exhausts?