Code P0300 and engine running rough after replacing the timing chain?

I also replaced the plugs and plug wires. And I checked all of the grounds. I cleaned my throttle body, and I cleaned the mass airflow sensor.

Yes, if you are off a tooth on the timing chain it will not run correctly. Here is a video of the job being done so you can compare what you did to see if it is correct:

https://youtu.be/mrp9YXPaYFg?si=p0yGPJJ2jmkl61BC

Please check the image below as well, Also, this can be a vacuum leak so I would go over this guide as well:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Check out the images (below). Please let us know what happens.

Thank you for the reply. I pulled the timing cover and checked. I was a tooth off. I got it lined up correctly. I also replaced all 8 coil packs. I am still getting the P0300 code, and the engine is running rough. Any suggestions on what to check next?

Lets do a compression test to see if the engine is in good shape with no bent valves. You can rent a compression gauge for free at the auto parts store FYI.

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

Please go over this guide and get back to us.

Thank you for your support. I will do the compression test. I have a compression gauge. I will let you know what happens. Again, thank you so much.

np, we like helping people :)