Code P0306

The engine light is flashing because the o2 sensors are sensing the misfire is causing raw fuel to come through the exhaust and can damage the exhaust or engine.

So clearly it is important to figure this out so that the damage is not done.

Here is a guide that will get us started:

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Also, we are going to have to check the compression on this cylinder and a couple others just to get a baseline.

Here is a guide that will help with this:

https://www.2carpros.com/articles/how-to-test-engine-compression

Let us know what questions you have and what you find. Thanks