What else can we check? We have replaced the spark plugs and both coil packs. We are still getting the codes for misfires. It has gotten better but is still happening
What year? How many miles?
I’ll add to wires checking the compression, and then the fuel injectors. Inspect the wiring harness & plugs, do a simple listen (tick-tick-tick - use a small piece of hose). You can also buy a noid light from auto parts stores. If you have a repair manual it will tell you how to check them with a multimeter.
When it comes to misfiring cylinders that are adjacent to each other a head gasket could be the suspect.
Run a compression test for starters.
Another possibility if the engine is distributor equipped is a carbon tracked or cracked dist. cap.
This can be caused by a chronic misfire.