* Fuel System Issues: This is a very common cause. Problems could include:
* Clogged fuel filter: A restricted fuel filter prevents the engine from getting enough fuel.
* Faulty fuel pump: The pump might be weak, delivering insufficient pressure.
* Dirty fuel injectors: Clogged injectors can't spray fuel properly. This often leads to a rough idle and sputtering.
* Low fuel pressure: This could be due to a failing fuel pressure regulator.
* Bad fuel: Contaminated or low-quality gasoline can cause similar symptoms.
* Mass Airflow Sensor (MAF) Problems: The MAF sensor measures the amount of air entering the engine. A faulty sensor provides incorrect information to the computer, leading to a poor air/fuel mixture and sputtering.
* Throttle Body Issues: A dirty or malfunctioning throttle body can interfere with airflow.
* PCV Valve: A clogged Positive Crankcase Ventilation valve can cause a buildup of pressure in the crankcase, affecting engine performance.
* Oxygen Sensor(s): Faulty oxygen sensors provide inaccurate readings to the engine control module (ECM), resulting in improper fuel mixture and rough running.
* Vacuum Leaks: A leak in the vacuum system can disrupt the air/fuel mixture.
* Ignition Control Module (ICM): Even though you've replaced the plugs, the ICM could still be faulty and causing intermittent problems. This is less likely if the plugs *were* the problem before replacement.
* Crankshaft Position Sensor (CKP): A faulty CKP sensor prevents the engine from knowing its rotational position, leading to misfires.
Troubleshooting Steps:
1. Check for Diagnostic Trouble Codes (DTCs): Use an OBD-II scanner to read any stored trouble codes. This will often pinpoint the problem area.
2. Inspect the fuel filter and fuel pressure: A visual inspection of the fuel filter can reveal clogging, and a fuel pressure gauge test will verify sufficient fuel pressure.
3. Clean the throttle body: A dirty throttle body can cause problems. Clean it with a throttle body cleaner.
4. Check for vacuum leaks: Listen for hissing sounds around vacuum lines and components.
5. Consider the MAF sensor: If you have access to a parts store's diagnostic tools, they may test your MAF sensor.
Important Note: Without a proper diagnostic scan, pinpointing the exact cause is difficult. It's best to take your Escape to a qualified mechanic for diagnosis and repair if you're not comfortable performing these checks yourself. Attempting repairs without the proper knowledge can potentially worsen the problem or cause damage to other components.
