2000 Mazda Protege code P0420

Tiny
ZEMORZEMOR
  • MEMBER
  • 2000 MAZDA PROTEGE
  • 1.6L
  • 4 CYL
  • FWD
  • MANUAL
  • 160,000 MILES
What causes this code and how to diagnosis the causes?
Wednesday, April 1st, 2015 AT 10:30 PM

10 Replies

Tiny
WRENCHTECH
  • MECHANIC
  • 20,757 POSTS
The means that the Catalytic Converter for bank one is not doing it's job correctly. On rare occasions a leak in the exhaust can cause that code but 95% of the time that is a bad Converter.
Was this
answer
helpful?
Yes
No
Thursday, April 2nd, 2015 AT 2:19 AM
Tiny
ZEMORZEMOR
  • MEMBER
  • 486 POSTS
There is black sooth in the exhaust do you think its clogged?I want to figure out why the cat is bad before I put a new one.

What can causes a cat to go bad thank you
Was this
answer
helpful?
Yes
No
Thursday, April 2nd, 2015 AT 8:55 AM
Tiny
ZEMORZEMOR
  • MEMBER
  • 486 POSTS
There is black sooth in the exhaust do you think its clogged?I want to figure out why the cat is bad before I put a new one. I checked the temperature of the converter at the outlet it was 540 F

What can causes a cat to go bad

thank you
Was this
answer
helpful?
Yes
No
+1
Thursday, April 2nd, 2015 AT 2:03 PM
Tiny
WRENCHTECH
  • MECHANIC
  • 20,757 POSTS
Any sort of contamination from a malfunctioning engine will take out a Cat. If you have any misfiring or coolant being burned, that will contaminate it. Just seeing black soot doesn't mean much. All exhaust has soot in it.
Was this
answer
helpful?
Yes
No
Thursday, April 2nd, 2015 AT 3:02 PM
Tiny
ZEMORZEMOR
  • MEMBER
  • 486 POSTS
Ok so I need a scan tool to do that. What is the most best Pc scan tools that I can get?
Was this
answer
helpful?
Yes
No
Friday, April 3rd, 2015 AT 8:08 AM
Tiny
ZEMORZEMOR
  • MEMBER
  • 486 POSTS
I put a bottle of techron fuel system cleaner and the check engine light did not come back. All monitors are ready. What you think?
Was this
answer
helpful?
Yes
No
Tuesday, April 7th, 2015 AT 9:42 PM
Tiny
WRENCHTECH
  • MECHANIC
  • 20,757 POSTS
There is no such thing as "Mechanic in a Can". It will be back.
Was this
answer
helpful?
Yes
No
Wednesday, April 8th, 2015 AT 1:58 AM
Tiny
ZEMORZEMOR
  • MEMBER
  • 486 POSTS
What is the first thing that I need to check first before I replace the catalytic
Was this
answer
helpful?
Yes
No
Thursday, April 9th, 2015 AT 8:05 AM
Tiny
WRENCHTECH
  • MECHANIC
  • 20,757 POSTS
For any leaks in the exhaust near the converter.
Was this
answer
helpful?
Yes
No
Thursday, April 9th, 2015 AT 8:48 AM
Tiny
ZEMORZEMOR
  • MEMBER
  • 486 POSTS
The check engine light went off now. Is this normal and what could causes it?
Was this
answer
helpful?
Yes
No
Sunday, April 26th, 2015 AT 10:31 AM

Please login or register to post a reply.

Sponsored links