After I change ignition coils RPMs do not go past 300?

It must be something wrong with a connector not being plugged in. Please go over your work again and if everything looks okay let's run the codes. Please check out this guide and get back to me. You can get a CAN scanner (Controller Area Network) from Amazon for about $36.00.

Here is a video to show you how:

https://youtu.be/u-4syLc-ifQ

Here is a scanner link:

https://amzn.to/3eCqWWw