Possible Causes & Troubleshooting:
* Clogged Catalytic Converter: A clogged catalytic converter restricts exhaust flow, leading to stalling. A mechanic can check backpressure in the exhaust system.
* Faulty Mass Airflow Sensor (MAF) Sensor: The MAF sensor measures the amount of air entering the engine. A faulty sensor provides inaccurate readings, leading to poor fuel mixture and stalling. Cleaning the sensor (carefully!) or replacing it might help. A diagnostic scan can often detect MAF sensor problems.
* Ignition System Problems: This includes issues with spark plugs, ignition coils, distributor cap (if applicable), and ignition wires. Check for worn or damaged components. A misfire can lead to stalling.
* Fuel System Problems: This could include a clogged fuel filter, a weak fuel pump, or problems with fuel injectors. A mechanic can check fuel pressure and injector operation.
* Vacuum Leaks: Leaks in the intake manifold or vacuum lines can disrupt the air/fuel mixture. Inspect hoses and connections for cracks or damage.
* Throttle Position Sensor (TPS): A faulty TPS can provide incorrect information about the throttle position to the engine control unit (ECU), leading to stalling. A diagnostic scan can reveal TPS problems.
* Crankshaft Position Sensor (CKP) or Camshaft Position Sensor (CMP): These sensors tell the ECU the engine's rotational position. Faulty sensors can cause misfires and stalling. A diagnostic scan is crucial here.
* Engine Control Module (ECU): While less common, a faulty ECU can cause a variety of problems, including stalling. This is usually diagnosed by a professional with specialized equipment.
* Low Fuel Pressure: Check the fuel pressure. A low reading points towards fuel pump issues.
What to do:
1. Get a Diagnostic Scan: This is the most crucial step. A scan tool can read diagnostic trouble codes (DTCs) from the car's ECU, pointing to specific problems. Auto parts stores often offer free scans.
2. Check Engine for other codes: If there are multiple codes, addressing them in order of priority can help.
3. Inspect the Obvious: Check the basics, such as ensuring you have enough fuel, and visually inspecting hoses, wires, and connections for obvious damage.
4. Professional Mechanic: If you're uncomfortable working on your car's systems, or if the diagnostic scan reveals complex issues, it's best to take it to a qualified mechanic. They have the tools and expertise to diagnose and fix the problem efficiently.
Replacing the oxygen sensor was a good first step, but don't assume that's the only issue. Stalling is often a symptom of a more significant underlying problem. A diagnostic scan is the key to finding the root cause.
