The three incidents occurred within a week of each other earlier this month.
Gardaí are investigating the theft of three catalytic converters in Offaly.
Two of the devices were stolen from cars in Banagher on Friday, the 11th of November.
The other converter was stolen from a vehicle in Birr on Friday, the 18th of November.
Gardaí are appealing for witnesses who may have camera or dashcam footage to come forward.
Anyone with any information is being asked to contact Birr Garda Station.