2003 lesabre service engine light is on

I have a 2003 lesabre, runs terrible. Had the computer codes read. Several codes came up.
1) po202 fuel injector open cicuit faulty # 2 cylinder
2) po204 " " " " " # 4 cylinder
3) po206 " " " " " # 6 cylinder
4) po300 randon/multiples cylinders misfire detected

I installed new plugs, wires and 3 coil packs, still runs rough. Feels like it's going to stall at stop signs, no power, makes a heck of a noise when idling. Anyone have any ideas on how to repair this problem, it has 48,000 miles on it. Thanks.
Tim
Found the problem, hate to say it. Was a blown fuse for injector bank #1. Thought I'd pass this on.

Random/ Multiple misses diffenitely sounds like a bad ignition coil...
Looks like its missing on the even cylinders.
You changed coil packs too.

Friend of mines had a 98 Mercedes Benz random missess like you have. Puttering when he stoped. Replaced the Ignition coil and it was smooth as a babys butt after that.

Puzzled... too