How to Clean the Three-Way Catalytic Converter of a Heavy Truck?
2 Answers
The cleaning method for the three-way catalytic converter of a heavy truck is the intravenous drip method. This method involves connecting a plastic hose to the engine's vacuum solenoid valve and using the air pressure in the hollow tube to draw the cleaning agent from the infusion bottle into the engine. As the cleaning agent is expelled through the exhaust pipe, it cleans the three-way catalytic converter. Modern vehicles are all equipped with three-way catalytic converters. Only vehicles produced in earlier years that did not meet the National II emission standards lack a three-way catalytic converter. Composition of the Three-Way Catalytic Converter: The three-way catalytic converter generally consists of four parts: the shell, damping layer, substrate, and catalyst coating. The shell is made of stainless steel to prevent oxide scale from falling off, which could clog the substrate. The damping layer is composed of padding or wire mesh pads, which serve to seal, insulate, and secure the substrate. To protect the substrate from damage due to vibration, thermal deformation, and other factors, the padding is made of expanded mica and aluminum silicate fibers, bonded together with adhesive. The substrate is made of honeycomb-shaped ceramic material, though many also use metal (including stainless steel) materials. The catalyst consists of precious metals such as platinum, rhodium, and palladium, which are sprayed onto the substrate to form the purifying agent.
I've cleaned the catalytic converters of large trucks many times. The first step is to check for blockages using diagnostic tools like an OBD scanner. If the oxygen sensor readings are abnormal, it's time for cleaning. Due to the large size of truck catalytic converters, it's best to remove them for treatment. I prepare specialized catalytic converter cleaner, carefully remove the converter, soak it in cleaning solution for several hours to soften carbon deposits, then use a high-pressure water gun to flush the channels, ensuring no residue remains. Before reassembly, it must be dried to avoid corrosion. Safety-wise, the exhaust system is dangerously hot, so gloves and goggles are a must—I learned this the hard way after getting burned once. After cleaning, emissions improve, and the truck accelerates more smoothly. However, I recommend going to a professional shop—they have more experience and better tools. For prevention, use fuel additives regularly to reduce the need for frequent cleanings.
