code 21

1921 DODGE NEON
Avatar
PITAX1
  • MEMBER
  • 3 POSTS
i have a code 21 on a 95 neon, do you know what this is?
Mar 23, 2007 at 10:47 AM
Advertisement
Avatar
MERLIN2021
  • ✓ASE Certified Mechanic
  • 17,250 POSTS
  • ASE Certified Mechanic
21 Oxygen sensor signal doesn't change (stays at 4.3-4.5V). Probably bad oxygen sensor
Mar 27, 2007 at 2:16 PM
Avatar
VASCOTT76
  • MEMBER
  • 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
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
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.