Rough Idle

2004 Mazda 3 S Sedan
Hey everyone. I have a 2004 Mazda3 S with 130,000 miles. I am having an issue with rough idle. It has thrown CELs.

The code tells me it is a misfire on cylinder 1. When I first start the car cold it will idle at about 900 to a thousand. If I drive the car and then shut it off and restart it, she will idle at around 500. Sometimes it dies at stop lights. Poor throttle response as well and gas mileage too. I have changed spark plugs cleaned the Maf and throttle body and changed out the coil packs. Anyone have any suggestions as to what I should try next?

I was thinking about changing out the injectors but I'm beginning to think I’m throwing good money after bad. EGR valve? Help please. I have owned the car from day one and really want to get this figured out.

Thank you.