I'm getting misfire codes on #1 and #2 cyl. What do I need to do to fix it on 2002 Jeep Grand Cherokee

I get P0300 P0301 P0302 codes. I have changed all 8 plugs and the coils for cyls 1 & 2 and still get the same codes. And the engine is still running rough. What could be next? Is there something in common with cyl 1 & 2 that can be changed? Thanks.

Asked by for the 2002 Jeep Grand Cherokee
check fuel injectors
Thanks. I'll try that.