2003 Toyota Corolla code 420

2003 TOYOTA COROLLA
200,000 MILES • 4 CYL • 2WD • AUTOMATIC
Avatar
PREPCUTIE258
  • MEMBER
  • 1 POST
I live in A county where you have to have emissions to get a tag and my car won't pass emissions becuase of code 420 which is "catilist system is running below threshold (bank 1) and I am wondering what exactly that means i'm not sure if that means i need a new catalistic coverter or it could just be an 02 censor. If you could be any help that would be great! Thanks!
Aug 5, 2009 at 10:51 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.
Advertisement
Avatar
MHPAUTOS
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 31,937 POSTS
Hi there,

you will need to check the cat converter, the 02 sensor and the wiring to to ECU, as this is a heated O2 sensor, i would check this function first.

mark (mhpautos)
Aug 5, 2009 at 11:01 PM
Advertisement