This indicates that the engine's air/fuel mixture is too rich on Bank 1. Bank 1 refers to one side of the engine (usually the side with cylinder #1). "Too rich" means there's too much fuel being injected relative to the amount of air entering the combustion chamber.
Possible Causes:
* Mass Airflow Sensor (MAF) sensor: A faulty MAF sensor can provide inaccurate readings to the engine computer (ECM), leading to excessive fuel injection. This is a common culprit.
* Oxygen Sensor (O2 sensor): A malfunctioning O2 sensor, particularly the upstream sensor on Bank 1, prevents accurate feedback on the air/fuel mixture, resulting in a rich condition.
* Fuel Injectors: A leaking or sticking fuel injector on Bank 1 can inject too much fuel.
* Fuel Pressure Regulator: A faulty regulator may allow too much fuel pressure in the system.
* Vacuum Leaks: Leaks in the intake manifold or vacuum lines can affect the air/fuel ratio. A large vacuum leak can cause a lean condition, but small leaks can sometimes lead to rich conditions due to the ECM's compensatory actions.
* PCV Valve: A clogged Positive Crankcase Ventilation valve can cause a buildup of pressure that impacts the air/fuel mixture.
Troubleshooting Steps (Generally should be done by a mechanic):
1. Check the MAF sensor: Inspect it for damage, clean it with MAF sensor cleaner (following instructions carefully), or replace it if necessary.
2. Check the O2 sensor(s) on Bank 1: Have them tested or replaced if needed.
3. Inspect for vacuum leaks: Carefully examine all vacuum lines and the intake manifold for cracks or loose connections.
4. Check fuel pressure: This requires specialized tools and usually involves a mechanic.
5. Inspect fuel injectors: Testing fuel injectors is best left to professionals.
Important Note: Simply clearing the code without addressing the underlying cause will likely result in the code returning. Proper diagnosis and repair are essential. It's highly recommended to take your 2003 Chevy Venture to a qualified mechanic for diagnosis and repair to prevent further engine damage.
