Carbon monoxide (CO) and hydrocarbon (HC) gasses are produced from the motor vehicle. This type of gasses is so dangerous for human and environment. Adsorption is one of the main methods for air purification systems. Pollutant adsorption using activated carbon is the best option because of its cost-effective and high possibility to remove pollutant components. Utilization of plastic waste as a raw material for activated carbon (AC) production continues to be developed. LDPE wastes could be considered as a favorable precursor because containing a high percentage of carbon. Surface modification of AC was done through metal oxide impregnation. TiO2 was used to increase its affinity towards CO and HC. The effects of the adsorption conditions such as adsorption tube length (3 cm, 4 cm, and 5 cm) were examined. This tube was connected to the vehicle exhaust pipe and gas analyzer on the other side. TiO2 impregnation was successful in increasing the surface area of AC up to 370.86 m2/g. Adsorption efficiency was achieved up to 74.83% and 67.10% for CO and HC respectively. The results showed that modification using TiO2 was effective to increase the adsorption capability of AC.