Code P0135, runs rough?

The code P0135 is O2 sensor heater circuit bank 1 sensor 1. so, that will not make the engine run rough, but you do need to replace the sensor. Are there no other codes? If not, we need to do a compression test, while you have the spark plugs out look at their condition the spark plugs that look different will be the cylinder that is having the problem. here is a guide to help you with the job, you can rent the gauge from the auto parts store for cheap or free. You can just upload a short video of the engine cranking over and I can tell if the compression is okay as well.

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

Let us know what happens and please upload pictures or videos of the problem.

Nice work, I would replace the #2- and #3-cylinders fuel injectors.

Here is a generic guide to show you how with instructions below to show you on your car:

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

Check out the images (below). Please let us know what happens. Don't forget to replace the oxygen sensor.

Yes, definitely a weak spark can cause the problem.

Yep, that is where I was going next here is how you can change out the ignition coils in the images below. Check out the images (below). Please let us know what you find.

Good to hear, please use 2CarPros anytime we are here to help. Thanks for getting back to us.