599 spitting sound one side exhaust.

Came my place change rpm sensor(s).36K km. Same spitting issue was before rpm sensors replace. It make it only idling, no sport mufflers. only one side spitting/slurs. litter/micro rev and all good, drive like v12 must. Same side have issue whith canister purge valve what i change and some ****ty piping works in engine bay(Japan classic), but still spitting. Calculatet fuel mass is 10% different in idling both side. One strange issue what i see my diagnostic tool(launch x8?? something)is both side exhaust temp is -25ć and catalytic calculated temp is -50ć after engine is running 30min and longer. But diagnostic dont show no fault.

 

It was left side MAF sensor error.I Flip sensors and solved problem. Buying new ones and purring like kitty now.