Reduced engine performance?

Hi:

If you clear the codes, do the same ones return right away? Also, I realize you changed the coils and the plugs. Are you getting a good spark at the spark plug?

If you have a good spark, the next thing I would consider is checking the fuel pressure and the fuel injectors. Dirt may be an issue.

Since 3 of the 4 cylinders are misfiring, that tells me that they are working most of the time. Otherwise, it wouldn't run on one cylinder.

One other thought would be a partially plugged catalytic converter. That would cause a misfire and loss of power. '

I've attached three links below. Each one explains how to check each of the three things I mentioned. Take a look at them and let me know if you are comfortable performing them. My first test would be the fuel pressure.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator/

https://www.2carpros.com/articles/how-to-test-a-fuel-injector/

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter/

Let me know what you find or if you have other questions.

Take care,

Joe