How to fix a P0300 Diagnostic Code - Random Misfire?

What is your question?

A P0300 diagnostic code indicates a random or multiple misfire. I have a 2007 Jeep commander 4.7 V8, with 10300 miles. The Random miss firing just recently started, we started by putting the fuel injector cleaner in it. Nothing happen. Then we replaced the spark plugs to make sure that was not an issue, while doing that we check the fuel injector, "Autozone said it was most likely the fuel injectors," and looked new. Once completed the light turned off, that same day the check engine light came back on for random miss firing P0300 code. The next step I took was to take it to a jeep dealership service shops. Paid the $125 for the to diagnosis it P0300 code to figure out what exactly it was. They say it was to lower O2 sensor change that was causing the problem. We change both of those. That Didn't fix the issue either. Today Contact the jeep dealership service center and they said that I would have to repay the $125. Need some suggestion on what do to nexts. Help pleases?

What makes this problem better or worse?

P0300 random Miss firing .

How long has your 2007 Jeep Commander had this problem?

3 weeks