
The function of the car's catalytic converter is to enhance the purification effect of the vehicle's exhaust. If removed, it will have an impact. The following are the roles of the catalytic converter in a car: Principle of the catalytic converter: The catalytic converter refers to the process of converting harmful gases such as CO, HC, and NOx emitted from the car's exhaust into harmless carbon dioxide, water, and nitrogen through oxidation and reduction reactions. It mainly uses a catalytic converter, the core component of which is a porous ceramic material installed in a specially designed exhaust pipe. Effects of removing the catalytic converter: It increases the vehicle's exhaust emissions, as without the catalytic converter, the car's exhaust cannot be effectively purified, leading to emissions exceeding standards. It also reduces the car's power and increases fuel consumption. Additionally, removing the catalytic converter will cause the vehicle to fail its annual emissions inspection.

As a seasoned car enthusiast with over a decade of experience, I strongly advise against removing catalytic converters. While it may seem like exhaust flow improves, the ECU will detect abnormal emissions and automatically limit engine power, making your throttle response sluggish. That high-pitched whistling noise sounds like aircraft takeoff/landing - especially during downshift rev-matching, it's literally headache-inducing. It'll definitely fail annual inspections - last year when I helped my cousin with this, we spent 800 yuan on shady middlemen and almost got caught. Worst part? The exhaust fumes make trailing cars honk like crazy. Once got pulled over by traffic police who smelled it and nearly impounded the car. You're better off installing a performance catalytic converter - legal and hassle-free.

Last time, the mechanic at the repair shop told me that removing the catalytic converter is totally not worth it these days. The power gain is minimal, but the check engine light stays on like a lantern. Fuel consumption even goes up—my neighbor's modified Civic burned an extra 1.5 liters per 100km in real-world tests. The real kicker is failing the annual inspection and having to revert it. Even buying aftermarket parts on Taobao costs over 2,000 yuan, not counting labor. The worst part? Used catalytic converters are sometimes treated as stolen goods, requiring police station paperwork. This deal loses you more than just your pants—better off fixing the OEM part.

We female car owners dread the hassle the most. Last month, my best friend fell for the repair shop's trick of removing the catalytic converter, and now her car idles like a tractor. The mechanic claimed the oxygen sensor was poisoned and charged her 580 for a new one. She doesn't even dare to use the air recirculation mode anymore—that rotten egg smell at red lights seeps right through her skirt. Once, while picking up her kid from school, other parents complained, and even the security guard remembers her car's exhaust stench. In the end, she had to spend 3,200 on a new catalytic converter to fix it—a painful lesson learned.

I didn't realize how important catalytic converters were until I started working at the Environmental Protection Agency. After removing it, carbon monoxide levels skyrocket by 20 times, and hydrocarbons exceed 50 times, making your car comparable to a mobile poison gas bomb during traffic jams. A colleague tested it with an exhaust gas analyzer - cars without catalytic converters emit 42 times above national standards and face a 5,000 yuan fine if caught. Nowadays, annual inspection stations use high-definition cameras to photograph exhaust pipes, and every month someone in the car modification groups fails their re-inspection. If you really want to modify, switch to a 400-cell high-flow catalytic converter - it boosts horsepower by 8% and still passes inspections.


