99 Blazer p420 code

Tiny
TOM WOOP
  • MEMBER
  • 1999 CHEVROLET ASTRO
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 155 MILES
Changed everything. MSD 8, 5 mm spark cables, Cap, Rotor, change all O2 sensors at same time.
P420 still shows up. Engine runs real smooth. Cat converter 6 months old. Any thoughts.
Monday, November 29th, 2010 AT 12:43 AM

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