After driving for 9 years, the car dealer said that the exhaust gas could not pass. What's the problem? What should I do?

Hello, the problem of exhaust gas must have been encountered by everyone in the process of car review. Among the cars I know, the domestic brand Chery's exhaust gas is more sad, especially the old Chery car. In fact, the relationship between exhaust gas and car age is not absolute. It is no problem to use waste gas properly at ordinary times. If there is anything wrong with the tail gas, I will give the following suggestions:

1. Change the No.95 oil at a regular gas station one week before online testing.

2. Replace the air filter and clean the lower throttle.

3. Go to the high speed to pull the high speed and let the car run at high speed. Especially driving at low speed in urban areas all the year round.

4. Clean the three-way catalytic converter. The repair shop can basically clean it. Prices range from 100 to 300 yuan.

I believe that through this operation, the tail gas will pass smoothly. If not, we can only consider changing trains [tears]