How to Clean a Clogged Exhaust Pipe?
3 Answers
There is no way to clean a clogged exhaust pipe; if the blockage is severe, it should be replaced with a new one. The effects of a clogged exhaust pipe include: 1. Insufficient power, slow acceleration, inability for exhaust gases to exit and fresh air to enter; 2. Increased forced downshifts in automatic transmission vehicles, exhaust pipe blockage, and insufficient engine power. In most cases, the cause of exhaust pipe blockage is a lack of cleaning for the three-way catalytic converter. Maintenance for the three-way catalytic converter: 1. Use unleaded gasoline, as the three-way catalytic converter is highly sensitive to lead—gasoline containing lead can cause blockages; 2. Pay attention to maintenance—the throttle body and other components should ideally be cleaned every 10,000 kilometers. If cleaning the throttle body does not improve performance, the three-way catalytic converter should be cleaned.
Last time I encountered a muffled exhaust, revving the engine in place didn't help, so I just turned it off and let it cool for half an hour. I gently tapped the entire exhaust pipe with a rubber mallet, especially around the bends, and after a few thuds, I could hear carbon chunks falling off. Then, I made a small curved hook with some wire and reached into the tailpipe, actually pulling out quite a few hard black lumps. Finally, I used a long, thin hose to flush water into the tailpipe while tapping the pipe walls, and murky water mixed with carbon fragments came gushing out. After finishing, the exhaust sound was immediately much cleaner upon starting! Remember to wear thick gloves the whole time—rust is sharp.
There are two main areas to clean when the exhaust pipe is clogged: the tailpipe and the section with the catalytic converter. I usually start by removing the tailpipe, cutting open a plastic bottle, filling it with a specialized cleaning solution, and soaking the accumulated carbon deposits for half an hour before rinsing with a high-pressure water jet. If the mid-section is severely clogged, the exhaust pipe needs to be removed. Pour in two bottles of oxalic acid solution and let it sit vertically overnight to dissolve the sludge inside. The next day, shake the pipe vigorously to pour out the blackened liquid, repeating the rinsing process until the water runs clear. If cleaning proves too difficult, replacing the pipe might be the only option, as the labor cost for disassembly and cleaning at a repair shop can almost match the price of a new part.
