His comments come in the wake of a recent incident where three young women died, and another still receiving intensive care in hospital, due to carbon monoxide (CO) poisoning.
The four were found unconscious in an MPV at the parking lot of a petrol station in Sama Gagah, next to the North-South Expressway, on Wednesday.
Automotive studies academic Chew Kim Loong said the key reasons that CO could be leaked into a car was the removal of catalytic converters, the exhaust filter between the engine and the tailpipe and ageing cars.
He said the converters, which basically filters 60% of noxious gases produced by engines, are being removed by enthusiasts so as to boost the car’s performance.
Chew added that CO and other dangerous gases can find their way into the cabin through air-conditioning ducts and porous parts of the car.
“Many car exhaust shops do this. Cut out the catalytic converter, replace it with dummy boxes or ‘bullets’, which does not filter out anything. All for the sake of boosting performance.
“By doing this, they are putting their lives at greater risk, as the chances of CO entering your car would be high and at the same time, harming the environment.
“Those wanting power should opt for performance-type catalytic converters. But many take the short cut due to price, convenience and lack of enforcement,” the training manager at Despark College, Petaling Jaya, told FMT.
Chew said the other cause of CO leaks are heavily modified engines, where it is tuned to be fuel-rich, with unburnt fuel sent straight to the tailpipes.
“This unburnt petrol is pumped out as hydrocarbons in the exhaust. Inhalation of that is also dangerous.”
According to Chew, older cars also posed a risk, because many owners are ignorant of the need to inspect and make replacements to their exhaust systems.
He called for Puspakom to step in and advise drivers to do so.
“The computerised car diagnosis centre (in Puspakom) is equipped with tools to check vehicles for leaks of four gases — CO, hydrocarbons, nitrous oxide and carbon dioxide.
“That is why in some countries, they prefer you to scrap your cars after they reach five years. There is good reason for such a policy,” he said.
Chew said in light of the recent incident which left four women unconscious while napping in the car while leaving their engine on, it is inherent upon car manufacturers to warn drivers not to do so by stating them clearly in car manuals.
He also advised drivers not to sleep in the car with the engine running.
“However, if you have to sleep, then lower the windows to allow for cross ventilation of the cabin,” he said.
Chew said the air-conditioning system should be set to recirculate when stationary, leaving the fresh air (from outside) option switched on only when in motion.
“This is because CO is a light gas and dissipates easily in motion. That is why even with traffic jams, the CO is not a threat, because the vehicle is in motion and these gases would be swept away by the wind.
“The real enemy here is being stationary,” he said.
Chew called for transport and environmental regulators to carry out regular inspection of all cars that are heavily modified or over 10 years old, for excess emissions.
He said those who remove catalytic converters must be punished and ideally, all cars should not exceed 200 parts per million (ppm) in terms of exhaust emissions, referring to the standards set by the California state government in the United States.