Check Engine & Cruise Control Light Flashing

[Liam]

The 2016 Subaru Impreza has 136K miles. Since June, on four separate occasions, the Check Engine & Cruise Control Light has come on at first start of the morning which disables the cruise control. The dealer's service center stated the computer code indicates random misfires and seems to occur during cold starts. After the forth time, the service center will only recommend ajdusting the valves and performing carbon cleaning per a TSB, which would cost $3,500 - $3600.00 because they would have to pull the engine. The only other "unofficial" recommendation was to use fuel treatments for carbon buildup and hopefully the valves would become clean enough that the computer would clear the codes and reset the cruise control. Any thoughts would be highly appreciated.