The Euro norms require manufacturers to reduce the existing polluting emission levels in a more efficient manner by making certain technical changes in our vehicles.
The following changes normally will be made by manufacturers in order to have a Euro I compliant car. Typically, the following areas would require attention:
(a) carburetor retuning
(b) secondary air intake
(c) exhaust gas recirculation
(d) catalyser capacity increase
(e) trimetal coating in the catalyser.