code 21

1921 DODGE NEON
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PITAX1
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  • 3 POSTS
i have a code 21 on a 95 neon, do you know what this is?
Mar 23, 2007 at 10:47 AM
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MERLIN2021
  • CAR REPAIR CONTRIBUTOR
  • 17,250 POSTS
21 Oxygen sensor signal doesn't change (stays at 4.3-4.5V). Probably bad oxygen sensor
Mar 27, 2007 at 2:16 PM
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VASCOTT76
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  • 1 POST
WILL A CODE 21 ALSO CAUSE THE CAR TO HERK AND RUN ROUGH NOT ACCELERATE ALSO AND IS CODE 21 THE UPPER O2 OR LOWER BY THE CATALYTIC CONVERTER
Apr 18, 2008 at 12:30 PM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.