Context : Low-mass protostars drive powerful molecular outflows that can be observed with millimetre and submillimetre telescopes .
Various sulfuretted species are known to be bright in shocks and could be used to infer the physical and chemical conditions throughout the observed outflows .

Aims : The evolution of sulfur chemistry is studied along the outflows driven by the NGC1333-IRAS4A protobinary system located in the Perseus cloud to constrain the physical and chemical processes at work in shocks .

Methods : We observed various transitions from OCS , CS , SO , and SO _ { 2 } towards NGC1333-IRAS4A in the 1.3 , 2 , and 3mm bands using the IRAM NOrthern Extended Millimeter Array ( NOEMA ) and we interpreted the observations through the use of the Paris-Durham shock model .

Results : The targeted species clearly show different spatial emission along the two outflows driven by IRAS4A .
OCS is brighter on small and large scales along the south outflow driven by IRAS4A1 , whereas SO _ { 2 } is detected rather along the outflow driven by IRAS4A2 that is extended along the north east - south west ( NE-SW ) direction .
SO is detected at extremely high radial velocity up to +25 km s ^ { -1 } relative to the source velocity , clearly allowing us to distinguish the two outflows on small scales .
Column density ratio maps estimated from a rotational diagram analysis allowed us to confirm a clear gradient of the OCS/SO _ { 2 } column density ratio between the IRAS4A1 and IRAS4A2 outflows .
Analysis assuming non Local Thermodynamic Equilibrium of four SO _ { 2 } transitions towards several SiO emission peaks suggests that the observed gas should be associated with densities higher than 10 ^ { 5 } cm ^ { -3 } and relatively warm ( T > 100 K ) temperatures in most cases .

Conclusions : The observed chemical differentiation between the two outflows of the IRAS4A system could be explained by a different chemical history .
The outflow driven by IRAS4A1 is likely younger and more enriched in species initially formed in interstellar ices , such as OCS , and recently sputtered into the shock gas .
In contrast , the longer and likely older outflow triggered by IRAS4A2 is more enriched in species that have a gas phase origin , such as SO _ { 2 } .