What are codes p0402 and p0422?

2003 MERCEDES BENZ SL500
95,000 MILES • 5.0L • V8 • 2WD • AUTOMATIC
Avatar
OSCARINCV
  • MEMBER
  • 1 POST
Codes p0402 and p0422?? Emissions codes?
May 30, 2022 at 7:51 PM
Advertisement
Avatar
STRAILER
  • ✓ASE Certified Mechanic
  • 54,832 POSTS
  • ASE Certified Mechanic
The P0402 code is for the EGR system which is flowing too much gases and the P0422 code is for the catalytic converter is not working as it should for the bank one but it might be triggered because of the first code which should be fixed first. Lets remove the EGR valve so we can check it, this video will show you how, and I have included instructions and the location of the EGR valve in the diagrams below.

https://youtu.be/DqUCbbKdWf4


Check out the diagrams (below). Let us know what happens and please upload pictures or videos of the problem.

Images (Click to enlarge)
Professional Diagram for 2CarPros Members
Click here to log in and view diagram.
Professional Diagram for 2CarPros Members
Click here to log in and view diagram.
Professional Diagram for 2CarPros Members
Click here to log in and view diagram.
Professional Diagram for 2CarPros Members
Click here to log in and view diagram.
May 31, 2022 at 10:49 AM
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.