94 LC, Over the pass few months I have been chasing a engine stumbling issue while driving. No codes to help that issue. Yesterday the LC ran with no problems. Today my LC will not stay running, It starts then dies immediately. Pulled the following codes: 21, 42, 32 and 71(I always get this one). Code 21 Main oxygen sensor signal fault Code 32 Air flow meter circuit or Vacuum sensor signal fault Code 42 Vehicle speed sensor circuit Code 71 EGR system malfunction I have already replaced the Plugs, Wires, Cap and Rotor. Items to be replaced Fuel Filter and Filter Sock. Any help or suggestions would be greatly appreciated.