After closed to 9 months cycling experience around Bandar Utama area. I can confirm that if I can’t start at early morning around 7am. There will be a lot of cars on the street after 9am. The pollution is pretty serious. While climbing and my body need more O2. I will smell diesel, petrol, rubbish or garden open burning always all weekend i cycled.
I decided to get a air mask filter from Lazada. It was shipped from China. Everything looks good and washable. Initially I am worried about the air flow. But after tried today it is not as bad. Only imperfection is the filter coverage may have leakage after I looked into the detail of the filter.