high idle

This is not uncommon when you use a chemical that contains Methyl Ethyl Ketone. This will damage the throttle body, sensors, or fuel system components. Take a look at the process attached below.

Also, if there are no issues with the throttle body then you may need to just relearn the throttle. I attached this process as well.

However, we need to first start with checking for codes. If there are codes then we have another issue that we need to start there. Here is a guide that will help with this:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Let's run through this and go from there.