Changed spark plugs now engine idles rough and knocks when in reverse

The NGK plugs are Nickel core plugs. The Champion ones are Copper core plugs. That's probably your issue right there. Nickel core plugs give a hotter spark than copper core plugs do.

When you changed the plugs, did you pull all of them out at the same time? Or did you pull 1, replace it, put the wire/coil back into place, and then move to the next plug? If you did it the first way, then I bet you accidentally switched 2 of the wires/coils around. This is a very common mistake that people make, and it's why you should always do your plugs one at a time.

Also, make absolutely sure that the coils are properly connected to the plugs, and that their connectors are snugly connected as well.

Let us know and we'll go from there.

Good morning.

Just to add to the last tech make sure the plugs you installed were gaped properly. If one was dropped and closed the gap, it would explain the miss.

Roy

Yeah I looked it up and I do see what you're saying about the coils. And yes, spark strength is basically everything. I always only use the stock plugs in my cars. In this sense, manufacturers generally know what's best for their cars. Also, as ASE suggested, the gap can make a difference too. I always check the gap of the plugs before installing them, even if they're supposed to be pre-gapped.

Delayed ignition due to weak sparks will cause that noise when you put the engine under a load ie putting it in gear. Your issues all seem to circle back to the plugs. I highly suggest going back to the OEM plugs. If there was something wrong with them, get new ones. Just my opinion.

Let me ask you this: What was the original reason for changing the plugs? Was it running roughly or burning a lot of fuel? If so, being a 2016, is it not under warranty?

And you really cannot say that it did nothing when the knocking sound went away.