1999 Chevy Tahoe error code 420 , 430

190,000 MILES • V8 • 4WD • AUTOMATIC
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DANCESWITHFISH
  • MEMBER
  • 1 POST
somehow,,probably vandalized, diiesel fuel got in the gas tank.Drove to dlr immediately. Dlr dropped tank and cleaned, replaced 2 fouled plugs and wires, cleaned injectors. Car runs like a top but check engine light came on after a few hundred miles and stays on. Code 420 and 430.
I put in can of injector cleaner and drove to Florida and light went out for a few hundred miles and came back on. Do I need to replace O2 sensors, or plugs and wires
or , gasp, the cat converter? The car truly runs like new.
Any ideas? I plan on keeping the car for years
Feb 19, 2008 at 1:43 PM
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2CARPRO JACK
  • ✓Experienced Mechanic
  • 11,533 POSTS
You can try o2 sensors, but it might not fix it.Those are both "cat efficiency low" codes.Try the sensors first, they will be much cheaper than the cats.
Feb 19, 2008 at 11:28 PM
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