^this guyyy. lol. I wish I could boost my car. How's the auto holding up to it?

 

Tune needs to get dialed in. First and second seems fine. Too many rattle issues that I need to fix first. Seems like the trans is holding fine. I'm now learning that the 4T45 is SERIOUSLY dependent on the tune when its boosted. Otherwise it will shift all over the place under light throttle when in boost. Trial and error.

 

It seems like the 4t45e just doesnt like to choose a gear in general. lol Mines mostly stock and hunts for the right gear.

 

Im glad you posted this. I have a 06 2.4 non-sc/tc. My dad had a 09 with the 2.0 and my aunt had an 07 with the 2.4. My dad and I have driven all three and ALL THREE DO THIS. In fact mine does it at exactly 40 mph. Some streets in my area have a posted speed limit of 40 mph. I dont even need to look at the speedo anymore because when this shift thingy happens I know I'm doing the speed limit. Took it to the dealer when I still had warranty and the guy told me that almost ALL cobalts do this because of the massive difference in gearing. Although I find that hard to believe that GM would think that shift thingy is not a problem.

 

Yea they just keep on reflashing my tcm with new software and its good for a month or so, then it decides to act up again. idk why there isnt a recall on it yet.

 

Kind of resurrecting an old thread here but I'm still dealing with this problem. Bought a new TCM but still haven't installed it. I have sent in requests to Vince at Trifecta to see if he can flash my new TCM with my vin info. etc but I haven't got any response. Probably sent 4 messages. Will have to try to make it to the dealership if Vince doesn't get back to me. Thought he would by now.

I'd like to say that I'm "glad" to hear others have this same problem. but not glad really. too bad it's happening!