I believe that engine uses an electronic throttle. Meaning there is no adjustment. It also means that if you clean it it can have issues. Have you or someone else tried to clean it in the past? If so, this may be the source of the problem. Most cable-less throttle systems have a set up or reset procedure to put them in the proper “start” position if they become out of range.
This is difficult to confirm without being able to monitor the throttle with a scan tool. You would also need to know what you’re looking at on the scan tool to verify its operation. This information is often found in the factory service manual.
I often purchase factory service manuals for my vehicles for things just like this. I usually get them off eBay in physical, or often digital form. They are a great source of repair information for any vehicle. You might consider it. It may shed some light on the issue and keep you from replacing parts and hoping for a fix.
Good hunting and please keep us posted.