1999 Chevy S-10 P0171

1999 CHEVROLET S-10
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CARTMAN98
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1999 Chevy S-10 4 cyl Two Wheel Drive Manual 140k miles

My truck is running the p0171 code and the bad cat code as well. I knew my cat was going out for a while, but it didn't affect the engine performance. Last night the truck was smoking black exhaust and had hesitation, wouldn't climb above 45 unless I downshifted. I ran the code and the 171 code came up. Is this a 02 sensor that went out you think?
Jun 24, 2009 at 7:03 PM
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BLUELIGHTNIN6
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The faulty cat. converter has most likely caused the O2 sensors to fail, it is pretty common once the converter acts up.
Jun 24, 2009 at 7:29 PM
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CARTMAN98
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What is the best way to replace the cat? Aftermarket? Used? GM? I had the thing replaced maybe 2 years ago so I don't want the next one to go bad. Can salvage yards sell used cats?
Jun 24, 2009 at 9:10 PM
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BLUELIGHTNIN6
  • ✓ASE Certified Mechanic
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If you recently replaced it then you may want to look into why it failed so quickly. Check out your EGR system and other emission systems. I suggest using the dealer brand, not sure if salvage yards can sale them or not.
Jun 24, 2009 at 9:14 PM
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