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This study investigated the effects of injection pressure and split injection on exhaust odor and engine noise in DI diesel engines. At idle, an injection pressure of 60 to 80 MPa resulted in the minimum exhaust odor with the least aldehyde and minimum THC formation. This is because of decreases in fuel adhering to the combustion chamber walls due to the shortest ignition delay and improved mixture formation at this pressure range. However, above 60 MPa there is no further shortening of the ignition delay and overleaning of the local mixture dominates at injection pressures above 100 MPa, where the exhaust odor increases again. The higher injection pressure of 60 to 80 MPa is favorable for emission reductions, but there are increases in engine noise and engine instability at idle. To reduce engine noise, further experiments with split injection were attempted.