Driving with a bad fuel injector is possible for a short distance to get to a repair shop, but it's a risky practice that can cause significant and costly damage to your engine. The primary risk is that a malfunctioning injector can lead to a lean condition (too much air, not enough fuel) or a rich condition (too much fuel, not enough air) in the affected cylinder. Both scenarios are detrimental to engine health.
A lean condition can cause the engine to misfire—a noticeable shaking or stumbling sensation—and lead to overheating, which can damage the piston and valves. A rich condition, often characterized by black smoke from the exhaust and a strong gasoline smell, can wash away the protective oil film from the cylinder wall, accelerating piston ring and cylinder wear. It also contaminates the engine oil and can destroy the catalytic converter, one of the most expensive components to replace.
The severity of the damage depends on how the injector has failed. Here’s a breakdown of common symptoms and associated risks:
| Symptom | What It Means | Potential Risk if Driven Extensively |
|---|
| Engine Misfire | Injector is clogged or not spraying fuel properly. | Damage to catalytic converter; piston/valve damage from overheating. |
| Rough Idle | Uneven fuel delivery to the cylinders. | Increased engine wear; strain on engine mounts. |
| Poor Fuel Economy | Injector is stuck open, leaking fuel. | Washed cylinder walls; oil contamination; catalytic converter failure. |
| Strong Gasoline Smell | Fuel leak from a damaged injector seal or body. | Fire hazard; environmental pollution. |
| Check Engine Light | Engine control unit (ECU) detects a fuel trim or misfire issue. | Underlying damage is already occurring; further driving compounds it. |
If you suspect a bad injector, the safest course of action is to have the car towed to a mechanic. If you must drive it, keep the trip very short, avoid hard acceleration, and go directly to the repair facility. The cost of a tow is minimal compared to the expense of a new engine or catalytic converter.
