The car only ran 50000 kilometers in 6 years, why does the exhaust gas fail during the annual inspection?

A car owner reported that their car has been six years old and needs to be tested online for the first time in the annual audit. The car has only driven 50000 kilometers, and I thought there would be no problem, but I didn't expect the exhaust to be substandard. It is necessary to go to the designated repair shop for repair before it can be put online for testing. In fact, there are many vehicles in this situation, and there have been cases where the brake system of a new car was tested and found to be unqualified when it was launched. However, there were no abnormalities during the inspection at the 4S store, and it passed the test again when it was launched.

Unqualified exhaust gas is closely related to the maintenance and refueling of vehicles in daily life. If the mileage is still small, it is often caused by improper maintenance or due to the poor quality of gasoline added by oneself. There are several factors in terms of maintenance: air filter, gasoline filter, carbon buildup, and spark plugs. The air filter and steam filter are the most basic maintenance items. If they are not replaced for a long time, they will become very dirty, resulting in poor air intake, oil pressure not meeting standards, incomplete combustion, and ultimately unqualified exhaust gas.

       Secondly, there is the issue of carbon deposition. Although the mileage traveled is not significant, it depends on the road conditions during normal driving. If the road is congested every day and the vehicle is used for short distances, there will be a significant amount of carbon deposition after 50000 kilometers. Excessive carbon accumulation can lead to poor intake, poor atomization of fuel injection, incomplete combustion, and also unqualified exhaust gas. Finally, there is a spark plug that needs to be checked. If it is a regular spark plug, it has reached the mileage of 50000 kilometers and should be replaced in a timely manner. If it is a platinum spark plug and there is no missing cylinder phenomenon detected by the computer, then there is no need to consider the spark plug issue.

If there is no problem with the gasoline added and the regular maintenance items are completed on time, but the exhaust gas still does not meet the standard, then simply cleaning and carbon accumulation can basically solve the problem, without having to do many projects at the same time. If you often add some cheap gasoline and the quality of the oil cannot be determined, then in addition to cleaning the carbon deposits, ternary catalysis also needs to be cleaned at the same time. Due to poor gasoline, it is easy to cause ternary catalytic failure. Although there was no fault displayed or fault code at the time, its catalytic efficiency has decreased, but it has not yet reached the limit value for reporting the fault code. At this time, the exhaust gas will also appear unqualified. In the absence of a displayed fault code, only cleaning is necessary and no replacement is required. It is understood that when going to a repair shop to repair the exhaust gas that is not qualified, it is mostly recommended to replace the three-way catalytic converter first. If the owner does not replace it, they can also clean it first, but the effect is not guaranteed.

 Finally, let me talk about the issue of gasoline. Before the annual inspection of the vehicle, do not add fuel indiscriminately, and do not change the brand. For example, if you have been adding PetroChina all the time and there are no issues with the vehicle, then do not replace Sinopec before reviewing the vehicle. Although the oil products are all qualified, some vehicles may experience some problems after changing the oil. If there is a slight problem with gasoline combustion, the exhaust gas will be substandard. I used to refuel at a private small gas station, but before the annual inspection, I had to go to a larger regular gas station to refuel two boxes of fuel to ensure that there were no problems with the gasoline. No matter how many kilometers you go for online testing, you should prepare yourself first. As you approach the maintenance mileage, do the maintenance first to check for any carbon deposits. If there are any, clean them up in a timely manner, refuel and pay attention. The annual inspection can basically pass at once.

From: WONDEE Autoparts

2023-9-18