What are the symptoms of a failed catalytic converter?

[VonElaina]

The symptoms of a failed catalytic converter are: 1. Weak vehicle acceleration, low engine RPM, and difficulty increasing speed; 2. Automatic transmission vehicles frequently force downshifts; 3. Decreased engine power and excessive exhaust emissions; 4. Engine shaking, malfunction indicator light illumination, and frequent stalling; 5. Continuous heating of the exhaust pipe, potentially reaching the ignition point of nearby components and causing spontaneous combustion. Solutions for catalytic converter failure: 1. Remove the catalytic converter and soak/clean it with oxalic acid or toilet cleaner; 2. Replace the catalytic converter; 3. Add fuel additives and avoid using low-quality gasoline or fuel additives.

[HaileyLee]

Last time I took my old car on the highway, it felt obviously wrong - the power was sluggish, and even with the accelerator pedal floored, the speed couldn't reach 100 km/h. What's more annoying is the fuel consumption has skyrocketed. Previously, a full tank could run 500 km, but now the fuel light comes on after just over 400 km. The mechanic at the inspection station said my exhaust pipe was emitting blue smoke with a rotten egg smell, and the engine light on the dashboard also came on. This is most likely due to a clogged catalytic converter. Old cars are prone to this, especially if frequently driven short distances - severe carbon buildup in the exhaust treatment system can render it useless. Getting it fixed now would cost several thousand yuan.

[MacEliana]

A couple of days ago, my car's exhaust suddenly became extremely loud, rumbling annoyingly at red lights. When I popped the hood, I noticed reddish-brown rust particles leaking from the exhaust pipe connection, and the exhaust smelled burnt. The mechanic plugged a scanner into the OBD port, and it immediately showed fault code P0420, indicating catalytic converter efficiency below threshold. He explained that if the ceramic honeycomb structure inside the converter breaks and blocks the exhaust pipe, the engine would struggle like running with a mask on—no wonder the car shook badly when the AC was on recently.

[ColemanDella]

Students at our driving school have been complaining about the lack of acceleration in that training car recently. During my test, I noticed the exhaust pipe was abnormally hot to the touch. Normally, the exhaust pipe should be warm after regular driving, but this one was hot enough to fry an egg. The exhaust gas analyzer showed carbon monoxide levels five times higher than the standard, with particularly choking black smoke. Upon disassembling the oxygen sensor, I found it coated with a thick layer of white powder, a typical symptom of the precious metal coating inside the three-way catalytic converter peeling off, basically rendering its purification capability ineffective.

[StellaLee]

Attention all car modification enthusiasts! My car, which has been ECU-tuned, has been experiencing severe backfiring when I floor the accelerator recently. The repair shop used an endoscope to inspect the exhaust pipe and found that one-third of the ceramic honeycomb structure in the catalytic converter has collapsed. The mechanic explained that modified cars have higher exhaust temperatures, which can cause the honeycomb structure to sinter and melt easily. The broken fragments can also be carried by the exhaust flow into the muffler, causing secondary blockages. Now, the HC emission levels during the annual inspection are three times over the limit, and the only solution is to replace the entire catalytic converter.

[HectorAnn]

Our fleet truck drivers are most afraid of catalytic converter issues. One truck suddenly saw its urea consumption drop by half, while the exhaust gas temperature surged to 800°C. When parked at a service area, the exhaust pipe dripped a syrup-like sticky substance that bubbled upon contact with the ground. Upon disassembly, the catalytic converter was found to be clogged with a cement-like substance—this was catalyst poisoning caused by excessive phosphorus in the fuel additive, rendering it completely ineffective. During heavy-load uphill driving, there was a noticeable increase in exhaust backpressure, resulting in a power loss of around 15%.