Apparatus used to remove exhaust gas for cars, namely, air filters, exhaust pipes; Apparatus used to decrease exhaust gas for cars, namely, air filters, exhaust pipes; Filters used to remove exhaust gas for cars; Apparatus used to decrease exhaust gas for diesel vehicles, namely, air filters, exhaust pipes; Apparatus used to decrease nitrogen oxide materials for cars, namely, air filters, exhaust pipes; Apparatus used to decrease nitrogen oxide materials for diesel vehicles, namely, air filte...