Strictly speaking, it cannot pass the annual inspection because modifications to the exhaust system are not allowed. Any tampering with the exhaust system cannot be registered, let alone pass the annual review. Of course, in some regions, the enforcement of exhaust modifications is not very strict. As long as the exhaust sound is not too conspicuous, it generally won't be checked by traffic police on the road. However, it is not recommended to modify the exhaust system, as improper tuning can not only reduce engine performance but, more critically, affect driving safety. Below is relevant information: Hazards: Installing an exhaust valve not only allows you to control the exhaust sound at will but also more effectively manages exhaust backpressure, keeping the vehicle in optimal condition. However, if the opening and closing timing of the exhaust valve is inaccurate, it can be extremely detrimental to engine power output, especially at high speeds where smooth exhaust flow is crucial, leading to significant negative impacts. Effects: Converting a single exhaust to a dual exhaust can be done in two ways. One method involves welding a fake exhaust tip at the tailpipe to create the appearance of a dual exhaust, which has minimal impact on vehicle performance and thus no major drawbacks. The other method involves replacing the entire mid and tail sections of the exhaust. While this can improve exhaust flow, excessive smoothness reduces exhaust backpressure, resulting in a loss of low-end torque and affecting acceleration performance.
