Two technicians are discussing exhaust check valves used in SAI systems. Technician A says that they are used to prevent
the output from the SAI pump from entering the intake manifold. Technician B says the check valves are used to keep the
exhaust from entering the AIR pump. Which technician is correct?

a. Technician A only

b. Technician B only

c. Both Technicians A and B

d. Neither Technician A nor B

Technical B is right.

Explanation:

The first systems injected air very close to the engine, either in the cylinder head's exhaust ports or in the exhaust manifold

However, the extra heat of recombustion, particularly with an excessively rich exhaust caused by misfiring or a maladjusted carburetor, tended to damage exhaust valves and could even be seen to cause the exhaust manifold to incandesce.

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