2004 Ford F-150 P0581 Code: Why Does Check Engine Light Never Come On?

Model: 2004 F-150 Fault Code: P0581 Posted: 2020-02-23 20:37

My 2004 Ford F-150 shows a persistent misfire (P0300) every time I accelerate past 50 mph. Despite having multiple engine-related diagnostic codes, the check engine light has only come on once in nearly five years. The truck idles smoothly and runs well at lower speeds, but performance degrades noticeably above 50 mph. I've already replaced spark plugs and coils within the last year, and while there are several other codes stored in the system, none relate to the powertrain. Additionally, my ABS sensor is faulty and the ABS light remains on. I'm wondering why the check engine light doesn't illuminate more frequently despite clear misfire symptoms. Can this be attributed to a specific fault code or sensor issue? Any insights for a 2004 F-150 owner with P0300 and P0581 codes?