Volvo Penta 4.3GL Instruction Book page 13

Type Approval Number
A type approval number is assigned to an engine
model when it is certified for exhaust emissions.
There are two certification decals placed on the
A
engine to verify engine certification; one on the EFI
computer cover, and the other at the front of the port
cylinder head (A). These decals must be maintained
so engine certification can be verified in the future.
When an emissions check is required, the plug (B)
located on the port high-rise elbow can be removed
for installation of a test probe.
B
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