Emissions from systems that use a 
catalytic converter are substantially reduced by introducing 
hydrogen, or a 
hydrogen containing fluid or fuel component, into the exhaust 
stream being scrubbed by the 
catalytic converter, resulting in instant lightoff and a significant reduction in emissions. 
Hydrogen for injection into the exhaust 
stream may, optionally, be generated within the vehicle using heat recovered from the 
catalytic converter, and / or the engine or elsewhere in the exhaust 
system, by a 
thermoelectric generator, the electrical output of which may be used to perform 
electrolysis and / or to power a reformer in order to generate the 
hydrogen. The 
thermoelectric generator may be retrofit onto the catalytic converter, or integrated in a way that enhances thermoelectric generation, including providing a catalyst coated 
heat sink and integrated cooling pipes to enhance the thermal differential required for thermoelectric generation. Sensors such as an 
oxygen sensor and temperature sensor may be provided to assess converter performance and adjust the temperature differential to ensure that the temperature of the converter remains optimum.