2018 Chevy Silverado 1500 8 speed misfire or trans issue

[14wntr]

I have tried in vain to do my due diligence in searching for this problem and am now asking for help.

The problem I am experiencing is my truck feels like it is misfiring under light acceleration and the problem is only getting worse. I thought it was bad gas at first and for the last year I am only putting in premium non ethanol. It has been a while since I last did a valve cleaning but it has been done. When the truck fully warms up it is not as bad but still present. I am not convinced it is not the trans. About 12k ago I changed the trans fluid JIC. No change. The truck runs and feels best when it is first started in the AM and run for a few miles. After that it starts bucking. There is no backfire or other issues. I am at a loss....

It is the worst in the warm up phase of the trans. 

The only mod is a catch can and a Range AFM disabler

I did unplug the Range to see if that helped and it did not at all 

Any help or suggestions are GREATLY appreciated! 

Truck has 55k on it

[CKNSLS]

2 hours ago, 14wntr said:

I have tried in vain to do my due diligence in searching for this problem and am now asking for help.

The problem I am experiencing is my truck feels like it is misfiring under light acceleration and the problem is only getting worse. I thought it was bad gas at first and for the last year I am only putting in premium non ethanol. It has been a while since I last did a valve cleaning but it has been done. When the truck fully warms up it is not as bad but still present. I am not convinced it is not the trans. About 12k ago I changed the trans fluid JIC. No change. The truck runs and feels best when it is first started in the AM and run for a few miles. After that it starts bucking. There is no backfire or other issues. I am at a loss....

It is the worst in the warm up phase of the trans. 

The only mod is a catch can and a Range AFM disabler

I did unplug the Range to see if that helped and it did not at all 

Any help or suggestions are GREATLY appreciated! 

Truck has 55k on it

You are 5,000 miles out of the power train warranty-however some dealers (with GM's OK) will cut you some slack. Have you been to the dealer to see if there are any codes stored that may tell them where to look?

[14wntr]

I have been to the dealer on this from early on. They told me they could not find anything on it. I will be taking it in again. Fortunately it is still under PT warranty due to buying it Certified

[14wntr]

I went back today. They took it for a drive and agreed there was a problem. They are doing a 20qt flush along with the filter under warranty as a start point. We will see...