What to Do When CO Emissions Exceed Standards?
4 Answers
CO is an intermediate product of incomplete fuel oxidation, which is produced when oxygen is insufficient. High concentration of the air-fuel mixture or uneven mixture distribution can increase CO emissions. Solutions for excessive CO emissions include: 1. Replace spark plugs: Faults in the ignition system, such as spark plugs or ignition coils, can cause excessive vehicle emissions. Poor-quality spark plugs can exacerbate emission pollution. 2. Replace with triple-side spark plugs to improve exhaust quality: Compared to single-side spark plugs, triple-side spark plugs feature a spark gap formed by multiple side electrodes and the cylindrical surface of the center electrode. This side-mounted spark gap eliminates the drawback of the side electrode covering the center electrode, thereby enhancing exhaust purification. 3. Clean spark plugs with sandpaper or a cleaning agent: Spark plugs are prone to carbon buildup and require regular cleaning.
I've seen quite a few cases of excessive exhaust emissions. The most common issue is too much carbon buildup clogging the fuel injectors and throttle valve, leading to incomplete combustion and strange exhaust odors. Before rushing to the repair shop and getting ripped off, try running two tanks of 95-octane gasoline with some proper fuel system cleaner to clear out the carbon deposits. If the spark plugs have been used for a long time, they should be replaced - those that have turned black are basically not working anymore. Another hidden factor is a lazy oxygen sensor; when it malfunctions, the computer will spray fuel haphazardly. Details like underinflated tires, dirty engine oil, and clogged air filters can also hold you back. If all else fails, go for an exhaust emission test and take the repair receipt for filing to avoid repeated hassle.
Last time my car failed the emission test, the experienced mechanic advised me to rev the engine for twenty minutes before heading to the inspection station, as a thoroughly warmed-up engine burns fuel more efficiently. Don’t drive too conservatively in daily use—make sure to take a half-hour highway run each month to shake out carbon deposits from the exhaust pipe. Modified cars require extra caution; while cold air intakes and straight-through exhausts sound great, they’ll guarantee emission failures. For older cars, replacing the catalytic converter in advance is more reliable than last-minute cleaning—aftermarket parts costing around 800 can last three years. Focus on checking the front oxygen sensor’s data stream; if voltage fluctuations exceed 0.45V, don’t push your luck.
Excessive exhaust emissions fall into three scenarios: black smoke indicates incomplete fuel combustion, white smoke means engine oil has entered the cylinders, and blue smoke usually requires cylinder head disassembly for repair. If you detect a rotten egg-like odor, immediately replace the catalytic converter as it cannot be salvaged once contaminated. My neighbor's car just got fixed - the diagnostic tool showed the rear oxygen sensor consistently reading above 0.8V, confirming complete catalytic converter failure. Be cautious when modifying circuits in older vehicles; oxygen sensor extension cables over 1 meter will definitely trigger errors. Before emissions testing, fill half the tank with E10 ethanol gasoline - some inspection stations respond favorably to this trick.
