2017 Ford Mustang 2.3L Ecoboost Premium Model P0304 Code: Diagnosis and Next Steps

Model: 2017 Ford Mustang 2.3 Ecoboost Prem. Fault Code: P0304 Posted: 2022-09-02 22:28

I recently noticed the MIL (Malfunction Indicator Lamp) coming on in my 2017 Ford Mustang 2.3L EcoBoost Premium model. After connecting a OBD2 scanner, I found a persistent P0304 code indicating a misfire on cylinder 4. I replaced the spark plugs and coil packs for that cylinder, as well as the fuel pressure sensor. After completing these repairs, I reset the system and cleared the code. The MIL turned off after about two days but reappeared again later. However, upon scanning, the P0304 code is now inactive — the ECM indicates it has completed its monitoring cycle and no longer considers the fault active. My question: Does this mean the issue has fully resolved? Or could the problem return in the future? I'm seeking clarity on whether further diagnostics or maintenance are needed to prevent recurrence, especially given that the P0304 code was triggered by a cylinder-specific misfire.