1 Three way catalytic converters are most effective if the m
1) Three way catalytic converters are most effective if the mixture is within (+/- 1%, +/- 5%, +/- 7%) of a stoichiometric mix.
2) A three way catalytic converter becomes (more efficient or less efficient) at converting CO when the mixture goes from lean to rich.
3) A catalytic converter based on platinum with a rhodium promoter has a light off temperature that is (higher, about the same as, or lower) compared to platinum by itself.
4) In the Lean NOx trap type of catalytic converter, rich operation after a period of lean operation, converts barium nitrate to barium carbonate. (true or false)
Solution
1. +7%
 2. more efficient
 3. Lower
4. True

