Driving with a confirmed catalytic converter issue is not recommended and should be avoided. While the car might still operate for a short period, doing so risks severe damage to your engine, significantly reduces fuel efficiency, creates harmful exhaust fumes, and is illegal in most areas due to emissions standards. The immediate course of action should be to have the vehicle diagnosed by a professional mechanic.
A failing catalytic converter, which is part of your car's exhaust system and responsible for converting harmful pollutants like carbon monoxide into less harmful gases, creates a major restriction in the exhaust flow. This backpressure can cause unburned fuel to overheat the converter, leading to internal melting or blockage. A fully clogged converter can cause the engine to stall completely and may even lead to a fire hazard from excessive heat.
Beyond drivability, the environmental and legal impacts are significant. You will fail an emissions test, and driving a car that emits excessive pollution can result in fines. The problem also won't fix itself; ignoring it will only lead to a more expensive repair.
| Symptom/Issue | Consequence of Ignoring It | Typical Repair Cost Range (USD) |
|---|
| Rotten egg smell from exhaust | Indicates converter is overheating and failing; can lead to meltdown. | $1,000 - $2,500 |
| Significant loss of engine power | Increased backpressure strains engine, potentially damaging pistons or valves. | $1,500 - $3,000+ |
| Check Engine Light (e.g., code P0420) | Failing emissions test; fines in states with mandatory testing. | $150 - $500 (diagnosis) |
| Loud rumbling noise from undercarriage | Worsening damage to exhaust system, potentially leading to complete failure. | $200 - $1,000 (exhaust repair) |
| Decreased fuel economy | Wasted money on gas; increased carbon deposits in the engine. | Varies with fuel price |
If you suspect a problem, get your car to a mechanic as soon as possible. The repair is costly, but the alternative of damaging your engine is far more expensive.
