Camaro zl1 2020 code saying p0420?

2020 CHEVROLET CAMARO
37,000 MILES • 6.2L • V8 • TURBO • 2WD • MANUAL
Avatar
SOLO987
  • MEMBER
  • 2 POSTS
Well I have been having problems with knock sensors. On both bank 1 and 2 and now I got a code saying p0420. And I have headers and a cold air intake on it.
Sep 5, 2025 at 5:33 PM
Advertisement
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.
Avatar
STRAILER
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 54,144 POSTS
Did you remove the catalytic converters? if so this will be the reason for the trouble code:

P0420 - Catalyst System Efficiency Below Threshold (Bank 1)

Please let me know.
Sep 6, 2025 at 4:29 PM
Avatar
SOLO987
  • MEMBER
  • 2 POSTS
Yeah I did. Im running kooks headers
Sep 6, 2025 at 4:34 PM
Advertisement
Avatar
STRAILER
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 54,144 POSTS
If you don't have cats you will have this code and the engine will not run at optimum performance. Believe it or not the engine is made to run at the best performance from the factory. Unless you plan a bunch of expensive engine and computer work is it best to leave it stock.
Sep 7, 2025 at 8:54 AM