(T) 1996 tempra 16sw ,keeps cutting out

hi all,my tempra starts cutting out when it warms up and rev counter goes a bit mad sometimes. had an snap on engine diag done today and was told the fault code is 121 evap canister purge valve,rang a fiat dealer for a price of new valve, told me he did'nt reconise the fault code as theirs are four digits. he said it would'nt be this but the throttle body costing £350. plus.anyhelp on this would be much appreciated