What to Do When Exhaust NO Levels Exceed Standards?
2 Answers
If the exhaust NO levels significantly exceed standards, the first step is to clean the cooling system and heat dissipation system, and even flush the lubrication system. Below are relevant details about exhaust treatment: 1. Control the flow of cleaning agent: The optimal flow rate should cause slight vibration in the engine at idle speed. If severe engine vibration occurs during cleaning, immediately reduce the cleaning agent flow. Some 4S shop technicians prioritize speed by injecting a large flow of cleaning agent quickly, which not only damages the engine but also reduces cleaning effectiveness. 2. Cleaning the catalytic converter: The catalytic converter should be cleaned and maintained every 30,000 kilometers, or every 10,000 kilometers if conditions permit. With proper maintenance, the catalytic converter's lifespan ranges from 150,000 to 200,000 kilometers before replacement is needed.
If excessive nitrogen oxide (NOx) emissions are detected, I would start by checking common fault points. For instance, a clogged or failed three-way catalytic converter is often the main culprit—over time, it can't effectively filter pollutants, so promptly inspect whether it needs cleaning or replacement. A faulty oxygen sensor can also mislead the engine control unit (ECU), leading to incomplete combustion and a spike in NOx levels; the simplest way is to use an OBD scanner to read error codes. Carbon buildup in fuel injectors can cause issues too—try adding a fuel system cleaner and taking a highway drive to see if it helps. Don’t forget engine carbon deposits—use decarbonization products or rev the engine at high speeds to clear them out. If these DIY fixes don’t work, a professional repair shop is necessary for a full diagnosis—they can optimize ECU settings or replace components. Routine maintenance is key: check spark plugs and engine oil every 5,000 km to prevent issues. Excessive emissions not only waste fuel but also pollute the air—timely fixes ensure safety, eco-friendliness, and smoother driving.
