1. Fuel Injector Fault
Fault Codes:
Fault codes such as P0201–P0204 (Cylinder Injector Circuit Fault) or P0300–P0304 (Random/Single Cylinder Misfire Detected) often appear when a fuel injector is not delivering the correct amount of fuel. These codes indicate irregular fuel delivery, electrical circuit faults, or injector clogging that leads to uneven combustion and poor engine performance.
Why it happens:
The VW Rabbit’s fuel injectors operate under constant heat and pressure. Over time, carbon buildup, dirty fuel, or internal wear affects how precisely the injector can deliver fuel. When the injector spray pattern becomes weak or inconsistent, the air–fuel mixture becomes unbalanced, causing rough running and reduced efficiency. In some cases, electrical failures inside the injector coil or wiring trigger fault codes and drivability issues.
Symptoms:
- Rough or unstable idle – The engine may shake or vibrate because one or more cylinders aren’t receiving the correct amount of fuel.
- Engine misfires – You’ll feel hesitation, stumbling, or sudden drops in power, especially during acceleration.
- Poor acceleration – The vehicle feels sluggish or unresponsive because the injector cannot supply enough fuel for proper combustion.
- Hard starting or extended cranking – Insufficient fuel delivery makes it difficult for the engine to fire up quickly.
- Increased fuel consumption – A faulty injector can cause either too much or too little fuel delivery, both of which reduce fuel economy.
- Fuel odor or rich running – Leaky injectors may cause raw fuel smell, black exhaust smoke, or fouled spark plugs.
- Check Engine Light activation – Misfire or injector circuit codes may appear during diagnostics.