CEL Flashing, Shaky Engine and Misfires

[KevinH1990]

Originally Posted by jamesmartin986

I'm not risking turning the engine on again until it's safe.

I think that is a good decision. I see that you are located in Spain and appreciate that you may not have a typical U.S. suburban garage in which you can DIY repairs. In the U.S. auto parts stores will normally read OBD II codes for you, but I don't know whether that is the case in Spain.

If you are interested in the process for diagnosing the flashing Check Engine Light, this video provides a decent outline.

https://www.youtube.com/watch?v=PK8pca8q5Zo

In the video, the presenter decided the spark plugs were defective. In my experience, I've found that spark plugs are a less likely source of the problem. Of the three flashing Check Engine Lights I've experienced, two were caused by defective coils and one was caused by a defective Mass Air Flow sensor. Based on this, I think it is likely you have a defective coil pack, but that is just a hunch. Replacing a coil on a Boxster requires jacking up the car, placing it on jack stands and removing the rear fender liner. It is not terribly difficult, but you need a safe place to work and appropriate tools. This video shows the process:

https://www.youtube.com/watch?v=H25qLssQNxg