DTC P0300 - Random Misfire Detected

Install scan tool. Start engine and check if DTC P0300 is present. If DTC is present, go to next step. If DTC is not present, problem is intermittent. See INTERMITTENTS in TESTS W/O CODES article.
Check ignition system to all cylinders. See BASIC TESTING article. Repair as necessary. If ignition system is okay, go to next step.
Check each fuel injector for proper operation. See BASIC TESTING article. Clean or replace as necessary. If injectors are okay, clear DTC. See CLEARING CODES under Self Diagnostic System section. Retest system. If DTC resets, replace ECM.