* Fuel injectors: The injector cleaner *might* help, but if the injectors are badly clogged or damaged from the poor fuel, they may need cleaning (professionally, with an ultrasonic cleaner) or replacing. Bad fuel can gum them up significantly.
* Fuel pump: The bad fuel could have damaged the fuel pump or its filter. A weak or failing fuel pump can't supply enough fuel at the right pressure, leading to hesitation and bucking.
* Mass Airflow Sensor (MAF) Sensor: Contaminated fuel can sometimes affect the MAF sensor, which measures the amount of air entering the engine. A dirty or faulty MAF sensor will cause incorrect fuel/air mixture calculations, resulting in poor performance.
* Throttle Position Sensor (TPS): Similar to the MAF sensor, a faulty TPS can disrupt the engine's fuel delivery.
* Spark plugs (again): While you replaced them, ensure they're the correct type for your engine and that the gap is properly set. Incorrectly gapped plugs can lead to misfires and poor running.
* Ignition coil(s): A faulty ignition coil can cause misfires in one or more cylinders, resulting in hesitation and bucking.
* Oxygen sensor(s): A bad oxygen sensor will give the engine's computer incorrect information about the exhaust gas composition, leading to poor fuel management.
What to do next:
1. Check for trouble codes: Use an OBD-II scanner to read any diagnostic trouble codes (DTCs) stored in your Explorer's computer. These codes can point you directly to the problem. Auto parts stores often offer free code reading services.
2. Fuel Pressure Test: Have a mechanic test the fuel pressure. This will determine if the fuel pump is delivering sufficient pressure.
3. Visual inspection: Have a mechanic visually inspect the fuel system for any signs of damage or debris from the bad fuel.
4. Professional diagnosis: If you're not comfortable tackling this yourself, take your Explorer to a qualified mechanic. They have the tools and expertise to diagnose the problem accurately and perform the necessary repairs.
Ignoring the problem could lead to further engine damage. Addressing it promptly is key.
