According to Sussex Police, officers stopped a vehicle, suspected to be involved in thefts, on the A259 near Arundel, at around 2am today (Tuesday, January 26),
The vehicle was searched and four catalytic converters were located in a concealed area accessed via the rear seat, police said.
Two men, aged 32 and 54, were arrested on suspicion of theft from a motor vehicle. Police said the pair remained in custody for questioning this afternoon.
DCI Simon Dunn said: "Catalytic converter theft can have a serious financial impact on victims and we are taking targeted action against thieves.
"There are a number of measures people can take to deter thieves, including parking in a secure or well-lit area and considering locks or guards.
"We also encourage people to continue reporting any thefts to us, so we can build a picture of the crimes and respond effectively."
Anyone who has been a victim of a catalytic converter theft, or who may have any other information including relevant CCTV, doorbell or dash cam footage, is asked to contact police online or by calling 101. Always dial 999 in an emergency.