Abstract: A catalytic converter comprises two catalytic matrices 10, 12, 14 mounted in a common housing and spaced from one another by an afterburner chamber 16. An igniter 22 is arranged in the afterburner chamber 16 near the first matrix 12 and a flame guard 18 is arranged upstream of and in close proximity to the igniter 22. The flame guard 18 comprises at least one elongate narrow strip spanning the combustion chamber which acts to spread the base of the flame across the width of the chamber 16 so as to enable the flame to spread in a shorter distance across the exhaust gases before reaching the second matrix 14.